| Origen (c. 185–c. 254), most distinguished and most influential of all the theologians of the ancient church |
| Orion and Orus, names of several Greek grammarians |
| Earl of Orkney, Scottish title |
| Elizabeth Hamilton, Countess of Orkney (1657?–1733), mistress of the English King William III. |
| Vittorio Emanuele Orlando (1860–1952), Italian statesman |
| Dukes of Orléans |
| Ferdinand-Philippe-Louis-Charles-Henri, duc d’Orléans (1810–1842), French noble |
| Prince Henri of Orléans (1867–1901), French noble |
| Henrietta-Anne, Duchesse d’Orléans (1644–1670), third daughter of the English King Charles I. |
| Gaston, duc d’Orléans (1608–1660), French noble |
| Louis, duc d’Orléans (1372–1407), French noble |
| Louis, duc d’Orléans (1703–1752), French noble |
| Louis Philippe, duc d’Orléans (1725–1785), French noble |
| Louis Philippe Joseph, duc d’Orléans (1747–1793), French noble, called Philippe Égalité |
| Philippe, duc d’Orléans (1640–1701), French noble |
| Philippe, duc d’Orléans (1674–1723), Regent of France |
| Philippe, duc d’Orléans (1869–1926), French noble |
| Bernard van Orley (1491–1542), Flemish painter |
| Orlov, name of a noble Russian family |
| Robert Orme (1728–1801), English historian of India |
| Eleanor Anne Ormerod (1828–1901), English entomologist |
| Ormin (fl. 1200?), author of an English book, called by himself Ormulum |
| Earl and Marquess of Ormonde |
| James Butler, Duke of Ormonde (1610–1688), Irish statesman and soldier |
| James Butler, Duke of Ormonde (1665–1745), Irish statesman and soldier |
| Orodes, name of two Parthian kings |
| Paulus Orosius (fl. 415), historian and theologian |
| Charles Boyle, Earl of Orrery (1676–1731), British author, soldier and statesman |
| Roger Boyle, Earl of Orrery (1621–1679), British soldier, statesman and dramatist |
| Alfred Guillaume Gabriel, Comte d’Orsay (1801–1852), famous dandy and wit |
| Orseolo, name of a Venetian family |
| Orsini, name of a Roman princely family of great antiquity |
| Felice Orsini (1819–1858), Italian revolutionist |
| Hans Christian Örsted (1777–1851), Danish physicist |
| Abraham Ortelius (1527–1598), Next to Mercator the greatest geographer of his age |
| Joseph-Louis-Elzéar Ortolan (1802–1873), French jurist |
| James Orton (1830–1877), American naturalist |
| Job Orton (1717–1783), English dissenting minister |
| Eliza Orzeszkowa (1842–1910), Polish novelist |
| Sherard Osborn (1822–1875), English admiral and Arctic explorer |
| Francis Osborne (1593–1659), eminent English writer |
| Oscar I. (1799–1859), King of Sweden and Norway |
| Oscar II. (1829–1907), King of Sweden and Norway |
| Osceola (1804–1838), Seminole chief |
| Frances Sargent Osgood (1811–1850), American poetess |
| Sir John O’Shanassy (1818–1883), British colonial statesman |
| Arthur William Edgar O’Shaughnessy (1844–1881), English poet |
| Andreas Osiander (1498–1552), German reformer |
| Sir William Osler (1849–1919), British physician and professor of medicine |
| Osman |
| Osman (1832–1900), Turkish pasha and mushir (field marshal) |
| Jerónimo Osório (1506–1580), Portuguese historian |
| Osroes |
| Ossian (Third Century), legendary Irish hero of Celtic literature |
| John Evelyn Denison, Viscount Ossington (1800–1873), English statesman |
| Thomas Butler, Earl of Ossory (1634–1680), Irish noble |
| Ostade, name of two Dutch painters |
| Andrei Ivanovich, Count Osterman (1687–1747), Russian statesman |
| Jean Frédéric Ostervald (1663–1747), Swiss Protestant divine |
| Alexander Nikolaivich Ostrovsky (1823–1886), Russian dramatic author |
| Oswald (604–642), King of Northumbria |
| Oswald (d. 992), Archbishop of York |
| Oswio (c. 612–670), King of Northumbria |
| Marcus Salvius Otho (32–69), Roman Emperor |
| Harrison Gray Otis (1765–1848), American politician |
| James Otis (1725–1783), American patriot |
| Otto (1815–1867), King of Greece |
| Otto I. (912–973), surnamed the Great, Roman Emperor |
| Otto II. (955–983), Roman Emperor |
| Otto III. (980–1002), Roman Emperor |
| Otto IV. (c. 1175–1218), Roman Emperor |
| Otto of Freising (c. 1114–1158), German Bishop and chronicler |
| Otto of Nordheim (d. 1083), Duke of Bavaria |
| Ottokar I. (d. 1230), King of Bohemia |
| Thomas Otway (1652–1685), English dramatist |
| Eugène-André Oudiné (1810–1887), French sculptor and medallist |
| Charles Nicolas Oudinot (1767–1847), Duke of Reggio, Marshal of France |
| William Oughtred (1575–1660), English mathematician |
| Ouida (Marie Louise de la Ramée) (1839–1908), English novelist |
| Walter William Ouless (1848–1933), English portrait-painter |
| Frederick Arthur Gore Ouseley (1825–1889), English composer |
| William Ouseley (1767–1842), British orientalist |
| Sir James Outram (1803–1863), English general |
| Johann Friedrich Overbeck (1789–1869), German painter |
| Sir Thomas Overbury (1581–1613), English poet and essayist |
| Samuel Jones Loyd, Baron Overstone (1796–1883), English banker |
| Ovid (43 B.C.–18 A.D.), Roman poet, the last of the Augustan age |
| Hugh Owen (1804–1881), Welsh educationist |
| John Owen (c. 1560–1622), Welsh epigrammatist |
| John Owen (1616–1683), English Nonconformist divine |
| Sir Richard Owen (1804–1892), English biologist |
| Robert Owen (1771–1858), English social reformer |
| John Owens (1790–1846), English merchant |
| Peder Oxe (1520–1575), Danish Finance Minister |
| John Oxenbridge (1608?–1674), English Nonconformist divine |
| John Oxenford (1812–1877), English dramatist |
| Henry Nutcombe Oxenham (1829–1888), English ecclesiologist |
| Oxenstjerna, ancient Swedish senatorial family |
| Earls of Oxford |
| Edward de Vere, Earl of Oxford (1550–1604), English noble |
| John de Vere, Earl of Oxford (1442–1513), English noble |
| Robert de Vere, 9th Earl of Oxford (1362–1392), English courtier |
| Robert Harley, Earl of Oxford (1661–1724), English statesman |
| Iwao Ōyama (1842–1916), Japanese field-marshal |
| Frédéric Ozanam (1813–1853), French scholar |
| Frederick Pabst (1836–1904), American brewer |
| William Paca (1740–1799), signer of the Declaration of Independence |
| Latinus Pacatus Drepanius (Fourth Century), one of the Latin panegyrists |
| Girolamo del Pacchia (1477–c. 1533) and Giacomo Pacchiarotto (1474–1540), two painters of the Sienese school |
| Richard Pace (c. 1482–1536), English diplomatist |
| Jean-Nicolas Pache (1746–1823), French politician |
| Francisco Pacheco (1571–1654), Spanish painter and art historian |
| Vladimir de Pachmann (1848–1933), Russian pianist |
| Saint Pachomius (292–346), Egyptian monk, the founder of Christian cenobitical life |
| Georgius Pachymeres (1242–c. 1310), Byzantine historian and miscellaneous writer |
| Otto von Pack (c. 1480–1537), German conspirator |
| Asa Packer (1805–1879), American capitalist |
| Simone Pacoret de Saint-Bon (1828–1892), Italian admiral |
| Pacorus, Parthian name, borne by two Parthian princes |
| Marcus Pacuvius (c. 220–130 B.C.), Roman tragic poet |
| Ignace Jan Paderewski (1860–1941), Polish pianist, composer and diplomat |
| Juan López de Padilla (1490–1521), insurrectionary leader |
| Paeonius (fl. 435 B.C.), Greek sculptor |
| Ferdinando Paër (1771–1839), Italian musical composer |
| José Antonio Páez (1790–1873), Venezuelan President |
| Pedro Paez (1564–1622), Jesuit missionary to Abyssinia |
| Nicolò Paganini (1782–1840), Italian virtuoso on the violin |
| Thomas Nelson Page (1853–1922), American author |
| Walter Hines Page (1855–1918), American editor and diplomatist |
| William Page (1811–1885), American artist |
| Sir James Paget (1814–1899), British surgeon |
| William Paget, Baron Paget of Beaudesert (1505/6–1563), English statesman |
| Édouard Pailleron (1834–1899), French poet and dramatist |
| Barry Pain (1864–1928), English humorous writer |
| Robert Treat Paine (1731–1814), signer of the Declaration of Independence |
| Robert Treat Paine, Jr. (1773–1811), American poet |
| Thomas Paine (1737–1809), English author |
| William Painter (1540?–1594), English author |
| Giovanni Paisiello (1740–1816), Italian musical composer |
| Claud Hamilton, Lord Paisley (c. 1543–1622), Scottish politician |
| Claude Pierre Pajol (1772–1844), French cavalry general |
| Augustin Pajou (1730–1809), French sculptor |
| Pakington, famous English Worcestershire family |
| Kristo Das Pal (1838–1884), Indian publicist |
| Armando Palacio Valdés (1853–1938), Spanish novelist and critic |
| František Palacký (1798–1876), Czech historian and politician |
| Quintus Remmius Palaemon (fl. First Century A.D.), Roman grammarian |
| Palaeologus, Byzantine family name |
| Palaephatus, author of a small extant treatise |
| José de Palafox y Melzi (1776?–1847), Duke of Saragossa |
| Juan de Palafox y Mendoza (1600–1659), Spanish Bishop |
| Aonio Paleario (1503–1570), Italian humanist and reformer |
| Giovanni Pierluigi da Palestrina (1525?–1594), Italian composer |
| Frederick Apthorp Paley (1815–1888), English classical scholar |
| William Paley (1743–1805), English divine and philosopher |
| John Gorham Palfrey (1796–1881), American historian |
| Sir Francis Palgrave (1788–1861), English historian |
| Francis Turner Palgrave (1824–1897), English critic and poet |
| Sir Robert Harry Inglis Palgrave (1827–1919), English banker and economist |
| Charles Guillaume Marie Appollinaire Antoine Cousin de Montauban, Comte de Palikao (1796–1878), French general and statesman |
| Charles Palissot de Montenoy (1730–1814), French author |
| Bernard Palissy (1510?–1589), French potter |
| Andrea Palladio (1508–1580), Italian architect |
| Rutilius Taurus Aemilianus Palladius (Fourth Century), Roman author |
| Peter Simon Pallas (1741–1811), German naturalist and traveller |
| Ferrante Pallavicino (1615–1644), Italian writer of pasquinades |
| Sforza Pallavicino (1607–1667), Italian Cardinal and historian |
| Johann Philipp Palm (1768–1806), German bookseller |
| Jacopo Palma (c. 1480–1528), Italian painter of the Venetian school |
| Alexander Mitchell Palmer (1872–1936), American politician |
| Sir Charles Mark Palmer (1822–1907), English shipbuilder |
| Edward Henry Palmer (1840–1882), English orientalist |
| Erastus Dow Palmer (1817–1904), American sculptor |
| George Palmer (1818–1897), British biscuit-manufacturer |
| John McAuley Palmer (1817–1900), American soldier and political leader |
| Ray Palmer (1808–1887), American clergyman and hymn-writer |
| Samuel Palmer (1805–1881), English landscape painter and etcher |
| Lord Palmerston (1784–1865), English statesman |
| Antonio Palomino de Castro y Velasco (1655–1726), Spanish painter and writer on art |
| Robert Paltock (1697–1767), English writer |
| Frederik Paludan-Müller (1809–1876), Danish poet |
| Pamphilus (First Century A.D.), Greek grammarian |
| Pamphilus (d. 309), eminent promoter of learning in the early church |
| Pamphilus (Fourth Century B.C.), Greek painter |
| Panaenus (Fifth Century B.C.), Greek painter |
| Panaetius (c. 185–180 to 110–108 B.C.), Greek Stoic philosopher |
| Pandulf (d. 1226), Roman ecclesiastical politician, papal legate to England and Bishop of Norwich |
| Count Nikita Ivanovich Panin (1718–1783), Russian statesman |
| Sir Anthony Panizzi (1797–1879), English librarian |
| Saint Pantaenus (fl. 180–200), head of the catechetical school at Alexandria |
| Panyasis (fl. 500–450 B.C.), Greek epic poet |
| Cesare Paoli (1840–1902), Italian historian and palæographer |
| Pasquale Paoli (1725–1807), Corsican general and patriot |
| Saint Papias (d. c. 120), one of the “Apostolic Fathers” |
| Denis Papin (1647–1714), French physicist |
| Louis Joseph Papineau (1786–1871), Canadian rebel and politician |
| Papinian (d. 212), Roman jurist, magister libellorum and afterwards praetorian prefect |
| Gottfried Heinrich von Pappenheim (1594–1632), Imperial field marshal in the Thirty Years’ War |
| Pappus of Alexandria (fl. c. Third Century), Greek geometer |
| Paracelsus (1493–1541), famous German physician |
| Hortensio Félix Paravicino y Arteaga (1580–1633), Spanish preacher and poet |
| Pardaillan, name of an old French family of Armagnac |
| Jean-Marie Pardessus (1772–1853), French lawyer |
| Emilia Pardo Bazán (1852–1921), Spanish author |
| Julia Pardoe (1806–1862), English writer |
| Ambroise Paré (1510?–1590), French surgeon |
| Juan de Pareja (1606–1670), Spanish painter |
| Simon-Napoléon Parent (1855–1920), Canadian politician |
| Giuseppe Parini (1729–1799), Italian poet |
| François de Paris (1690–1727), French theologian |
| Gaston Paris (1839–1903), French scholar |
| Louis-Philippe-Albert d’Orléans, Count of Paris (1838–1894), French noble |
| Matthew Paris (1200–1259), English monk and chronicler |
| Paulin Paris (1800–1881), French savant |
| Edwards Amasa Park (1808–1900), American Congregational theologian |
| Mungo Park (1771–1806), Scottish explorer of the Niger |
| Alton Brooks Parker (1852–1926), American lawyer |
| Sir Gilbert Parker (1862–1932), English novelist and politician |
| John Henry Parker (1806–1884), English writer on architecture |
| Horatio William Parker (1863–1919), American composer and musician |
| Sir Hyde Parker (1714–1782), British vice-admiral |
| Joseph Parker (1830–1902), English Nonconformist divine |
| Martin Parker (d. 1656?), English ballad-writer |
| Matthew Parker (1504–1575), Archbishop of Canterbury |
| Samuel Parker (1640–1688), English Bishop |
| Theodore Parker (1810–1860), American preacher and social reformer |
| Sir Harry Smith Parkes (1828–1885), English diplomatist |
| Sir Henry Parkes (1815–1896), Australian statesman |
| Charles Henry Parkhurst (1842–1933), clergyman and social reformer of New York City |
| George Robert Parkin (1846–1922), British Canadian educationist |
| James Parkinson (1755–1824), English palæontologist |
| Francis Parkman (1823–1893), American historian |
| Parmenides (fl. Early Fifth Century B.C.), Greek philosopher |
| Parmenion (c. 400–330 B.C.), Macedonian general |
| Parmigianino (1503–1540), celebrated painter of the Lombard school |
| Charles Stewart Parnell (1846–1891), Irish Nationalist leader |
| Sir Henry Parnell (1776–1842), English noble |
| Thomas Parnell (1679–1718), English poet |
| Évariste Parny (1753–1814), French poet |
| Catherine Parr (1512–1548), sixth queen of Henry VIII. |
| Samuel Parr (1747–1825), English schoolmaster |
| Thomas Parr (c. 1483–1635), English centenarian, known as “Old Parr” |
| Walter Parratt (1841–1924), English organist |
| Parrhasius (fl. Fifth Century B.C.), one of the greatest painters of Greece |
| Sir Charles Hubert Hastings Parry (1848–1918), English musical composer |
| Sir William Edward Parry (1790–1855), English rear-admiral and Arctic explorer |
| Robert Parsons (1546–1610), English Jesuit and political agitator |
| Samuel Holden Parsons (1737–1789), American soldier and jurist |
| Theophilus Parsons (1750–1813), American jurist |
| Thomas William Parsons (1819–1892), American author |
| Parthenius of Nicaea (First Century B.C.), Greek grammarian and poet |
| James Parton (1822–1891), American biographer |
| Bernard Partridge (1861–1945), British artist |
| William Ordway Partridge (1861–1930), American sculptor |
| Paolo Paruta (1540–1598), Venetian historian |
| Parysatis (Fifth Century B.C.), daughter of Artaxerxes I. |
| Blaise Pascal (1623–1662), French religious philosopher and mathematician |
| Jacqueline Pascal (1625–1661), sister of Blaise Pascal |
| Paschal, name of two popes, and one antipope |
| Saint Paschasius Radbertus (786–c. 860), French theologian |
| Giovanni Pascoli (1855–1912), Italian poet |
| Jules-Étienne Pasdeloup (1819–1887), French conductor |
| Pasiteles (First Century B.C.), most important member of the Neo-Attic school of sculpture |
| Ivan Fedorovich Paskevich (1782–1856), Russian field marshal |
| Sir Charles William Pasley (1780–1861), British soldier and military engineer |
| Étienne Pasquier (1529–1615), French lawyer and man of letters |
| Étienne-Denis Pasquier (1767–1862), French statesman |
| Bernardo Pasquini (1637–1710), Italian musical composer |
| Carlo Passaglia (1812–1887), Italian divine |
| Jean Passerat (1534–1602), French poet |
| Franz Passow (1786–1833), German classical scholar and lexicographer |
| Frédéric Passy (1822–1912), French economist and pacifist |
| Louis Pasteur (1822–1895), French chemist |
| Framjee Nasarwanjee Patel (1804–1894), Parsee merchant and philanthropist |
| Jules Patenôtre des Noyers (1845–1925), French diplomatist |
| Walter Pater (1839–1894), English man of letters |
| Robert Paterson (1715–1801), Scottish stonemason |
| William Paterson (1658–1719), British writer on finance, founder of the Bank of England and projector of the Darien scheme |
| Janet Monach Patey (1842–1894), English vocalist |
| José Patiño (1666–1736), Spanish statesman |
| Johann Reinhold Patkul (1660–1707), Livonian politician and agitator |
| Coventry Patmore (1823–1896), English poet and critic |
| John Brown Paton (1830–1911), British Nonconformist divine |
| Sir Joseph Noël Paton (1821–1901), British painter |
| Saint Patrick (373?–463?), patron saint of Ireland |
| Simon Patrick (1626–1707), English divine |
| Francesco Patrizi (1529–1597), Italian philosopher and scientist |
| Patrocles (c. 312–261 B.C.), Macedonian general and writer on geographical subjects |
| Fred Lewis Pattee (1863–1950), American educationist and author |
| Daniel Tod Patterson (1786–1839), American naval officer |
| Robert Patterson (1792–1881), American soldier |
| John Coleridge Patteson (1827–1871), English missionary, Bishop of Melanesia |
| Adelina Patti (1843–1919), English singer |
| Mark Pattison (1813–1884), English author and rector of Lincoln College, Oxford |
| Francis Landey Patton (1843–1932), American educationalist and theologian |
| Saint Paul, “the Apostle of the Gentiles,” first great Christian missionary and theologian |
| Paul, name of five popes |
| Paul I. (1754–1801), Emperor of Russia |
| Paul of Samosata (fl. 260–272), Patriarch of Antioch |
| James Kirke Paulding (1778–1860), American writer and politician |
| Paulet, English family of an ancient Somersetshire stock |
| Reinhold Pauli (1823–1882), German historian |
| Saint Paulinus of Nola (c. 353–431), successively a consul, a monk and a Bishop |
| Paulinus (d. 644), first Bishop of the Northumbrians and Archbishop of York |
| Lucius Aemilius Paullus Macedonicus (c. 229–160 B.C.), Roman general |
| Friedrich Paulsen (1846–1908), German philosopher and educationalist |
| Heinrich Eberhard Gottlob Paulus (1761–1851), German rationalistic theologian |
| Paulus Diaconus (c. 720–c. 800), historian of the Lombards |
| Paulus Silentiarius (Sixth Century), Greek poet |
| Julian Pauncefote (1828–1902), English diplomatist |
| Pausanias (d. c. 470 B.C.), Spartan regent and commander |
| Pausanias (c. 110–180 A.D.), Greek traveller and geographer |
| Pausias (c. 380–c. 330 B.C.), Greek painter |
| Manuel Pavía y Lacy, Marqués de Novaliches (1814–1896), Spanish marshal |
| Manuel Pavía y Rodríguez de Albuquerque (1828–1895), Spanish general |
| Sir Joseph Paxton (1801–1865), English architect and ornamental gardener |
| James Payn (1830–1898), English novelist |
| John Payne (1842–1916), English poet |
| John Howard Payne (1791–1852), American author |
| Peter Payne (c. 1380–c. 1455), English Lollard and Taborite |
| Edward Payson (1783–1827), American Congregational preacher |
| Péter Pázmány (1570–1637), Hungarian Cardinal and statesman |
| Mariano Felipe Paz Soldán (1821–1886), Peruvian historian and geographer |
| Andrew Preston Peabody (1811–1893), American clergyman and author |
| Elizabeth Palmer Peabody (1804–1894), American educationist |
| George Peabody (1795–1869), American philanthropist |
| Charles William Peach (1800–1886), British naturalist and geologist |
| Henry Peacham (c. 1576–c. 1643), English writer |
| Sir Barnes Peacock (1810–1890), English judge |
| George Peacock (1791–1858), English mathematician |
| Thomas Love Peacock (1785–1866), English novelist and poet |
| Charles Willson Peale (1741–1827), American portrait painter |
| Rembrandt Peale (1778–1860), American artist |
| Charles Sprague Pearce (1851–1914), American artist |
| Sir Edwin Pears (1835–1919), British lawyer and man of letters |
| Robert Lucas de Pearsall (1795–1856), English composer |
| Padraic Pearse (1879–1916), Irish educationist, author, and Sinn Fein leader |
| Charles Henry Pearson (1830–1894), British historian and colonial statesman |
| Bishop John Pearson (1612–1686), English divine and scholar |
| John Loughborough Pearson (1817–1897), English architect |
| Robert Edwin Peary (1856–1920), American Arctic explorer |
| Edward Pease (1767–1858), founder of a famous industrial Quaker family in the north of England |
| Félix Pécaut (1828–1898), French educationalist |
| Carl Fredrik Pechlin (1720–1796), Swedish politician and demagogue |
| Harry Thurston Peck (1856–1914), American philologist |
| John Peckham (d. 1292), Archbishop of Canterbury |
| Reginald Pecock (c. 1395–1460), English prelate and writer |
| Alexander Peden (c. 1626–1686), Scottish divine, one of the leading forces in the Covenant movement |
| Christiern Pedersen (1480?–1554), Danish writer, known as the “father of Danish literature” |
| Pedro II. (1825–1891), Emperor of Brazil |
| Pedro López de Ayala (1332–1407), Spanish statesman, historian and poet |
| Arthur Wellesley, Viscount Peel (1829–1912), English statesman |
| Sir Robert Peel (1788–1850), English statesman
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