;Bishops and archbishops of
Ottawa •
Joseph-Eugène-Bruno Guigues (1847–1874) •
Joseph-Thomas Duhamel (1874–1909) •
Charles-Hughes Gauthier (1910–1922) •
Joseph-Médard Émard (1922–1927) •
Joseph-Guillaume-Laurent Forbes (1928–1940) •
Alexandre Vachon (1940–1953) •
Marie-Joseph Lemieux (1953–1966), appointed titular Archbishop and nuncio •
Joseph-Aurèle Plourde (1967–1989) •
Marcel André J. Gervais (1989–2007) •
Terrence Prendergast, S.J. (2007–2020) ;Archbishops of Ottawa-Cornwall • Terrence Prendergast, S.J. (May 2020–Dec 2020) •
Marcel Damphousse (2020– )
Coadjutor bishops •
Alexandre Vachon (1939-1940) •
Marcel André J. Gervais (1989) •
Marcel Damphousse (2020- )
Auxiliary bishops •
Maxime Tessier (1951-1953), appointed Coadjutor Bishop of Timmins, Ontario •
Paul-Émile Charbonneau (1960-1963), appointed Bishop of Hull, Québec •
Joseph Raymond Windle (1960-1969), appointed Coadjutor Bishop of Pembroke, Ontario •
René Audet (1963-1968), appointed Bishop of Joliette, Québec •
John Michael Behan (1977-1988) •
Gilles Bélisle (1977-1993) •
Brendan Michael O'Brien (1987-1993), appointed Bishop of Pembroke, Ontario •
Paul Marchand,
SSM (1993-1999), appointed Bishop of Timmins, Ontario •
Frederick Joseph Colli (1994-1999), appointed Bishop of Thunder Bay, Ontario •
Christian Riesbeck,
CC (2014-2019), appointed Bishop of Saint John, New Brunswick •
Yvan Mathieu,
S.M. (2022- )
Other priests of this diocese who became bishops •
John Thomas McNally, appointed Bishop of Calgary, Alberta, in 1913 •
François-Xavier Brunet, appointed Bishop of Mont-Laurier, Québec, in 1913 •
Joseph Charbonneau, appointed Bishop of Hearst, Ontario in 1939 •
Jean Gratton, appointed Bishop of Mont-Laurier, Québec, in 1978 •
Jean-Louis Plouffe, appointed Auxiliary Bishop of Sault Sainte Marie, Ontario in 1986 •
José Avelino Bettencourt, appointed nuncio and titular archbishop in 2018 ==Statistics==