The Roman Catholic Diocese of San Justo is located in the city of San Justo, in the province of Buenos Aires. It was established by Pope Paul VI on 18 July 1969.
Bishops
Ordinaries
- Jorge Carlos Carreras (1969 – 1982), retired
- Rodolfo Bufano (1982 – 1990)
- Jorge Arturo Meinvielle, S.D.B. (1991 – 2003)
- Baldomero Carlos Martini (2004 – 2014), retired
- Eduardo Horacio García (2014 – Present)
Auxiliary bishops
- Rodolfo Bufano (1978-1980), appointed Bishop of Chascomús (later returned here as Bishop)
- Antonio Federico Gatti (1996-1998)
- Damián Santiago Bitar (2008-2010), appointed Bishop of Oberá
Other priest of this diocese who became bishop
- Juan Horacio Suárez, appointed Bishop of Gregorio de Laferrere in 2000