This topic deals with enforcing court judgments that are already made, but from a jurisdiction other than Ontario. There are three categories of these: foreign (except UK) judgments, UK judgments and Canadian (but non-Ontario) judgments.
The procedure for foreign judgments is under the common law. It involves commencing an Ontario civil proceeding, but - at least with respect to a foreign money judgment - requiring only that basic principles of fairness are met.
The procedures for UK judgments are governed by the Reciprocal Enforcement of Judgments (UK) Act [REJA(UK)A]. Other provincial or territorial judgments are governed by the Reciprocal Enforcement of Judgments Act [REJA].
The related issue of how to advance international litigation (from scratch) is addressed with under Private International Law.