Alphonsus is a masculine given name and surname which may refer to:
Given name Alphonsus Carroll (1895–1974), New Zealand dual-code international rugby union and rugby league footballer Alphonsus Cassell (1949–2010), aka Arrow (musician), Montserratian calypso and soca musician Alphonsus Ciacconius (1530–1599), Spanish Dominican scholar Alphonsus Cullinan (born 1959), Irish Roman Catholic prelate and Bishop of Waterford and Lismore Alphonsus Rick Doerr (born 1960), American Paralympic sailor Alphonsus J. Donlon (1867–1923), American Jesuit Alphonsus F. D'Souza (1939–2016), Indian Jesuit priest and Roman Catholic bishop Fonse Faour (born 1951), Canadian politician Alphonsus de Guimaraens (1870–1921), Brazilian poet Alphonsus Obi Igbeke (born 1962), Nigerian politician Alphonsus Gerald Irona, 21st century Nigerian politician Alphonsus Longgap Komsol, 21st century Nigerian politician Alphonsus Liguori (1696–1787), Roman Catholic Saint Alphonsus Mathias (1928–2024), Indian Roman Catholic archbishop Alphie McCourt (1940–2016), Irish-American writer Alphonsus Uche Mefor (born 1972), British-Nigerian pro-Biafra political activist Alphonsus Nwosu (born 1944), Nigerian politician, parasitologist, academic, administrator and former Minister of Health Alphonsus Liguori Penney (born 1924), Canadian Roman Catholic priest Alphonsus Josephus de Ridder (1882–1960), pen name Willem Elsschot, Belgian writer and poet Alphonsus Rodriguez (1532–1617), Spanish Jesuit and saint Alphonsus a Sancta Maria (1396–1456), Spanish historian Alphonsus Salmeron (1515–1585), Spanish biblical scholar, Catholic priest and one of the first Jesuits Alphonsus Augustus Sowada (1933–2014), American Roman Catholic bishop, cultural anthropologist and bishop Alonso Tostado (c. 1410–1455), also known as Alphonsus Tostatus, Spanish theologian, councillor of John II of Castile and briefly bishop of Ávila
Surname Aniekeme Alphonsus (born 1999), Nigerian sprinter and middle-distance runner Joy Alphonsus (born 1987), Nigerian-born actress
See also Petrus Alphonsi (or Petrus Alfonsus) (1062–1110), Spanish Jewish writer St. Alphonsus Church (disambiguation)