Diocese of Saint-Jean–Longueuil Dioecesis Sancti Ioannis–Longoliensis Diocèse de Saint-Jean Longueuil
Location
Country	Canada
Territory	Montérégie
Ecclesiastical province	Archdiocese of Montréal
Coordinates	45°32′25″N 73°30′28″W / 45.54028°N 73.50778°W / 45.54028; -73.50778
Statistics
Area	2,078 km2 (802 sq mi)
Population - Total - Catholics	762,240[1] 634,425 (83.2%)
Parishes	45
Information
Denomination	Catholic Church
Rite	Roman Rite
Established	June 9, 1933
Cathedral	Cathedral of Saint-Jean-l'Évangéliste
Co-cathedral	Co-Cathedral of Saint-Antoine-de-Padoue
Patron saint	John the Evangelist
Secular priests	60
Current leadership
Pope	Francis
Bishop	Claude Hamelin
Metropolitan Archbishop	Christian Lépine
Bishops emeritus	Lionel Gendron, P.S.S.
Website
dsjl.org

The Roman Catholic Diocese of Saint-Jean–Longueuil (Latin: Dioecesis Sancti Ioannis–Longoliensis) is a suffragan of the Metropolitan Archdiocese of Montréal in (mostly francophone) Québec, southeastern Canada.

Its cathedral episcopal see is the Cathédrale Saint-Jean-l’Évangéliste dedicated to John the Evangelist, in Saint-Jean-sur-Richelieu.

It has a Co-Cathedral: Cocathédrale Saint-Antoine-de-Padoue, dedicated to Saint Anthony of Padua, in Longueuil, Québec, and a Minor basilica: Basilique Sainte-Anne-de-Varennes, in Varennes, Québec.

• Erected on 9 June 1933, as the Diocese of Saint-Jean-de-Québec, on territory split off from the Archdiocese of Montréal, its Metropolitan.
• It was renamed on 27 February 1982 as Diocese of Saint-Jean–Longueuil / SanctiIoannis–Longolien(sis) (Latin).

As per 2015, it pastorally served 634,425 Catholics (83.2% of 762,240 total) on 2,078 km² (802 sq mi) in 45 parishes and 1 mission with 89 priests (60 diocesan, 29 religious), 4 deacons, 350 lay religious (99 brothers, 251 sisters) and 4 seminarians.

(all Roman Rite native Canadians)

Suffragan Bishops of Saint-Jean-de-Québec

• Paul-Ernest-Anastase Forget (1934.05.12 – death 1955.02.03)
• Gérard-Marie Coderre (1955.02.03 – retired 1978.05.03), died 1993; succeeded as former Titular Bishop of Ægæ (1951.07.05 – 1955.02.03) and Coadjutor Bishop of Saint-Jean-de-Québec (1951.07.05 – 1955.02.03)
• Bernard Hubert (1978.05.03 – 1982.02.27 see below), previously Bishop of Saint-Jérôme (Canada) (1971.06.25 – 1977.01.27), Coadjutor Bishop of Saint-Jean-de-Québec (1977.01.27 – 1978.05.03)

Suffragan Bishops of Saint-Jean-de-Longueuil

• Bernard Hubert (see above 1982.02.27 – death 1996.02.02), also President of Canadian Conference of Catholic Bishops (1985 – 1987)
• Jacques Berthelet, Viatorians (C.S.V.) (1996.12.27 – retired 2010.10.28), also President of Canadian Conference of Catholic Bishops (2001 – 2003); previously Superior General of Clerics of Saint Viator (Viatorians) (1984 – 1986.12.19), Titular Bishop of Lamsorti (1986.12.19 – 1996.12.27) as Auxiliary Bishop of Saint-Jean–Longueuil (1986.12.19 – succession 1996.12.27)
• Lionel Gendron, P.S.S. (28 October 2010 - retired 5 November 2019), also vice-president of Canadian Conference of Catholic Bishops (2015.09.15 – 2017.09.27); previously Titular Bishop of Tagase (2006.02.11 – 2010.10.28) as Auxiliary Bishop of Archdiocese of Montréal (Canada) (2006.02.11 – 2010.10.28)
  • Auxiliary Bishop (2004.06.19 – 2020.07.19): Louis Dicaire, Titular Bishop of Thizica (1999.02.18 – 2020.07.19), previously Auxiliary Bishop of Archdiocese of Montréal (Canada) (1999.02.18 – 2004.06.19)
  • Auxiliary Bishop (2015.12.22 – 2019.11.05): Claude Hamelin, Titular Bishop of Apollonia (2015.12.22 – 2019.11.05); next Bishop here
• Claude Hamelin (5 November 2019 – present)

• Gérard-Marie Coderre (1951–1955)
• Bernard Hubert (1977–1978)

• Robert Lebel (1974–1976), appointed Bishop of Valleyfield, Québec
• Jacques Berthelet, C.S.V. (1986–1996), appointed Bishop here
• Louis Dicaire (2004–2020)
• Claude Hamelin (2015–2019), appointed Bishop here

• Raymond Poisson, appointed Auxiliary Bishop of Saint-Jérôme, Québec in 2012

• List of Catholic dioceses in Canada

• GCatholic, with Google map - data for all sections
• Diocese of Saint-Jean-Longueuil site (in French)
• "Diocese of Saint-Jean-Longueuil". Catholic-Hierarchy. Retrieved 2007-03-15.