The Chaldean Catholic Eparchy of Mar Addai of Toronto is the sole eparchy (Eastern Catholic diocese) of the Chaldean Catholic Church (Syro-Oriental Rite) in Canada.

It depends directly on the Chaldean Catholic Patriarch of Babylon, but it not part of any ecclesiastical province.

Its cathedral is the Cathedral of the Good Shepherd, in North York, Toronto, Ontario.

[1] Seven priests and 40 permanent deacons preside over eight parishes, which are located in the provinces of Ontario and Quebec.

The eparchy was established on June 10, 2011 on territory previously not served by the Patriarchal particular church sui iuris.