The following men have led the Catholic Church as pope. An antipope is defined by the Catholic Encyclopedia as "a false claimant of the Holy See in opposition to a pontiff canonically elected."

St. Peter (32-67)
St. Linus (67-76)
St. Anacletus (Cletus) (76-88)
St. Clement I (88-97)
St. Evaristus (97-105)
St. Alexander I (105-115)
St. Sixtus I (115-125); also called Xystus I
St. Telesphorus (125-136)
St. Hyginus (136-140)
St. Pius I (140-155)
St. Anicetus (155-166)
St. Soter (166-175)
St. Eleutherius (175-189)
St. Victor I (189-199)
St. Zephyrinus (199-217)
St. Callistus I (217-22)
St. Hippolytus, Antipope (217-236)
St. Urban I (222-30)
St. Pontain (230-35)
St. Anterus (235-36)
St. Fabian (236-50)
St. Cornelius (251-53)
Novatian, Antipope (251)
St. Lucius I (253-54)
St. Stephen I (254-257)
St. Sixtus II (257-258)
St. Dionysius (260-268)
St. Felix I (269-274)
St. Eutychian (275-283)
St. Caius (283-296) -- also called Gaius
St. Marcellinus (296-304)
St. Marcellus I (308-309)
St. Eusebius (309 or 310)
St. Miltiades (311-14)
St. Sylvester I (314-35)
St. Marcus (336)
St. Julius I (337-52)
Liberius (352-66)
Felix II, Antipope (355-365)
St. Damasus I (366-83)
Ursicinus, Antipope (366-367)
St. Siricius (384-99)
St. Anastasius I (399-401)
St. Innocent I (401-17)
St. Zosimus (417-18)
St. Boniface I (418-22)
Eulalius, Antipope (418-419)
St. Celestine I (422-32)
St. Sixtus III (432-40)
St. Leo I (the Great) (440-61)
St. Hilarius (461-68)
St. Simplicius (468-83)
St. Felix III (II) (483-92)
St. Gelasius I (492-96)
Anastasius II (496-98)
St. Symmachus (498-514)
Laurentius, Antipope (498-501)
St. Hormisdas (514-23)
St. John I (523-26)
St. Felix IV (III) (526-30)
Boniface II (530-32)
Dioscorus, Antipope (530)
John II (533-35)
St. Agapetus I (535-36); also called Agapitus I
St. Silverius (536-37)
Vigilius (537-55)
Pelagius I (556-61)
John III (561-74)
Benedict I (575-79)
Pelagius II (579-90)
St. Gregory I (the Great) (590-604)
Sabinian (604-606)
Boniface III (607)
St. Boniface IV (608-15)
St. Deusdedit (Adeodatus I) (615-18)
Boniface V (619-25)
Honorius I (625-38)
Severinus (640)
John IV (640-42)
Theodore I (642-49)
St. Martin I (649-55)
St. Eugene I (655-57)
St. Vitalian (657-72)
Adeodatus (II) (672-76)
Donus (676-78)
St. Agatho (678-81)
St. Leo II (682-83)
St. Benedict II (684-85)
John V (685-86)
Conon (686-87)
St. Sergius I (687-701)
Theodore, Antipope (687)
Paschal, Antipope (687)
John VI (701-05)
John VII (705-07)
Sisinnius (708)
Constantine (708-15)
St. Gregory II (715-31)
St. Gregory III (731-41)
St. Zachary (741-52)
Stephen II (752)
Stephen III (752-57)
St. Paul I (757-67)
Stephen IV (767-72)
Constantine II, Antipope (767)
Philip, Antipope (768)
Adrian I (772-95)
St. Leo III (795-816)
Stephen V (816-17)
St. Paschal I (817-24)
Eugene II (824-27)
Valentine (827)
Gregory IV (827-44)
Sergius II (844-47)
John, Antipope (855)
St. Leo IV (847-55)
Benedict III (855-58)
Anastasius, Antipope (855)
St. Nicholas I (the Great) (858-67)
Adrian II (867-72)
John VIII (872-82)
Marinus I (882-84)
St. Adrian III (884-85)
Stephen VI (885-91)
Formosus (891-96)
Boniface VI (896)
Stephen VII (896-97)
Romanus (897)
Theodore II (897)
John IX (898-900)
Benedict IV (900-03)
Leo V (903)
Christopher, Antipope (903-904)
Sergius III (904-11)
Anastasius III (911-13)
Lando (913-14)
John X (914-28)
Leo VI (928)
Stephen VIII (929-31)
John XI (931-35)
Leo VII (936-39)
Stephen IX (939-42)
Marinus II (942-46)
Agapetus II (946-55)
John XII (955-63)
Leo VIII (963-64)
Benedict V (964)
John XIII (965-72)
Benedict VI (973-74)
Benedict VII (974-83)
Boniface VII, Antipope (974; 984-985)
John XIV (983-84)
John XV (985-96)
Gregory V (996-99)
John XVI, Antipope (997-998)
Sylvester II (999-1003)
John XVII (1003)
John XVIII (1003-09)
Sergius IV (1009-12)
Benedict VIII (1012-24)
Gregory, Antipope (1012)
John XIX (1024-32)
Benedict IX (1032-45)
Sylvester III (1045) -- Considered by some to be an antipope
Benedict IX (1045)
Gregory VI (1045-46)
Clement II (1046-47)
Benedict IX (1047-48)
Damasus II (1048)
St. Leo IX (1049-54)
Victor II (1055-57)
Stephen X (1057-58)
Nicholas II (1058-61)
Benedict X, Antipope (1058)
Alexander II (1061-73)
Honorius II, Antipope (1061-1072)
St. Gregory VII (1073-85)
Guibert ("Clement III"), Antipope (1080-1100)
Blessed Victor III (1086-87)
Blessed Urban II (1088-99)
Paschal II (1099-1118)
Theodoric, Antipope (1100)
Aleric, Antipope (1102)
Maginulf ("Sylvester IV"), Antipope (1105-1111)
Gelasius II (1118-19)
Burdin ("Gregory VIII"), Antipope (1118)
Honorius II (1124-30)
Celestine II, Antipope (1124)
Innocent II (1130-43)
Anacletus II, Antipope (1130-1138)
Gregory Conti ("Victor IV"), Antipope (1138)
Celestine II (1143-44)
Lucius II (1144-45)
Blessed Eugene III (1145-53)
Anastasius IV (1153-54)
Adrian IV (1154-59)
Octavius ("Victor IV"), Antipope (1159-1164)
Pascal III, Antipope (1165-1168)
Callistus III, Antipope (1168-1177)
Innocent III, Antipope (1178-1180)
Lucius III (1181-85)
Urban III (1185-87)
Clement III (1187-91)
Celestine III (1191-98)
Innocent III (1198-1216)
Honorius III (1216-27)
Gregory IX (1227-41)
Celestine IV (1241)
Innocent IV (1243-54)
Alexander IV (1254-61)
Urban IV (1261-64)
Clement IV (1265-68)
Blessed Gregory X (1271-76)
Blessed Innocent V (1276)
Adrian V (1276)
John XXI (1276-77)
Nicholas III (1277-80)
Martin IV (1281-85)
Honorius IV (1285-87)
Nicholas IV (1288-92)
St. Celestine V (1294)
Boniface VIII (1294-1303)
Blessed Benedict XI (1303-04)
Clement V (1305-14)
John XXII (1316-34)
Nicholas V, Antipope (1328-1330)
Benedict XII (1334-42)
Clement VI (1342-52)
Blessed Urban V (1362-70)
Gregory XI (1370-78)
Urban VI (1378-89)
Robert of Geneva ("Clement VII"), Antipope (1378-1394)
Boniface IX (1389-1404)
Pedro de Luna ("Benedict XIII"), Antipope (1394-1417)
Baldassare Cossa ("John XXIII"), Antipope (1400-1415)
Innocent VII (1404-06)
Gregory XII (1406-15)
Pietro Philarghi ("Alexander V"), Antipope (1409-1410)
Martin V (1417-31)
Eugene IV (1431-47)
Amadeus of Savoy ("Felix V"), Antipope (1439-1449)
Nicholas V (1447-55)
Callistus III (1455-58)
Pius II (1458-64)
Paul II (1464-71)
Sixtus IV (1471-84)
Innocent VIII (1484-92)
Alexander VI (1492-1503)
Pius III (1503)
Julius II (1503-13)
Leo X (1513-21)
Adrian VI (1522-23)
Clement VII (1523-34)
Paul III (1534-49)
Julius III (1550-55)
Marcellus II (1555)
Paul IV (1555-59)
Pius IV (1559-65)
St. Pius V (1566-72)
Gregory XIII (1572-85)
Sixtus V (1585-90)
Urban VII (1590)
Gregory XIV (1590-91)
Innocent IX (1591)
Clement VIII (1592-1605)
Leo XI (1605)
Paul V (1605-21)
Gregory XV (1621-23)
Urban VIII (1623-44)
Innocent X (1644-55)
Alexander VII (1655-67)
Clement IX (1667-69)
Clement X (1670-76)
Blessed Innocent XI (1676-89)
Alexander VIII (1689-91)
Innocent XII (1691-1700)
Clement XI (1700-21)
Innocent XIII (1721-24)
Benedict XIII (1724-30)
Clement XII (1730-40)
Benedict XIV (1740-58)
Clement XIII (1758-69)
Clement XIV (1769-74)
Pius VI (1775-99)
Pius VII (1800-23)
Leo XII (1823-29)
Pius VIII (1829-30)
Gregory XVI (1831-46)
Blessed Pius IX (1846-78)
Leo XIII (1878-1903)
St. Pius X (1903-14)
Benedict XV (1914-22)
Pius XI (1922-39)
Pius XII (1939-58)
Blessed John XXIII (1958-63)
Paul VI (1963-78)
John Paul I (1978)
John Paul II (1978-2005)
Benedict XVI (2005- )

Source: The Catholic Encyclopedia