I have a civil judgment (not child support or student loan) in a US state. My girlfriend would like me to move to Ontario and apply for permanent residence under her(she is Canadian). The US (state) judgment is still valid in that state but was rendered over 10 years ago. If the creditor filed this foreign judgment in Ontario court (the judgment is over $100,000) what would be the statute of limitations (in years) that I would file in my defense (in order to quash it is Ontario) and where can I find reference to this law or ruling through the net. Also, would it be effective if they filed to ask the court for a summary judgment in my favor based on the Ontario sol?

A US judgment cannot be filed in a Canadian court for enforcement.

Example: You lived in Detroit. You owe a US credit card $5000.00. You now work in Windsor, ON. You were sued in Michigan and were having your wages garnished in Michigan when you worked there. That garnishment and judgment cannot be enforced in Ontario. The creditor will have to wait for you to go back to US. Nothing on Canadian Credit Bureau about US debts. Moving to Canada is the same as moving to Antarctica as far as debt is concerned.

The basic limitation period in Ontario is 2 years. ( Google e-laws Ontario and look up Limitations Act to answer that part of your question.)