The list of 10 longest-reigning Popes:
- Pius IX (1846-1878): 31 years and 7 months.
- John Paul II (1978-present): 25 years, 4 months and 30 days or 9282 days as of March 15 2004, would pass Pius IX in 2010 if still reigning as Pope
- Leo XIII (1878-1903): 25 years, 4 months and 29 days (9281 days).
- Pope Pius VI (1775-1799): 24 years and 6 months (8962 days).
- Adrian I (772-795): 23 years and 10 months.
- Pius VII (1800-1823): 23 years and 5 months.
- Alexander III (1159-1181): 21 years, 11 months, and 23 days.
- St. Silvester I (314-335): 21 years and 11 months.
- St. Leo I (440-461): 21 years and 1 month.
- Urban VIII (1623-1644): almost 21 years
St. Peter (30 to 64/67 AD): 34 or 37 years, of which, according to tradition, he spent 25 in Rome. (Peter was not, however, known as pope in his lifetime)
See also List of 10 shortest-reigning Popes