As an American living in Canada, do I need to file tax returns in both countries?

A tax guide for American citizens in Canada

If you are a US citizen, there are quite a few filing requirements by the Internal Revenue Service (IRS) in the United States. If you are a U.S. citizen or resident alien living or traveling outside the United States, you are required to file income tax returns, estate tax returns, and gift tax returns and pay estimated tax in the same way as those residing in the United States. There are US Exclusions, which reduce the taxable amount of foreign-earned income as well as applicable tax credits for Canadian tax paid on the income. 

The standard form is a 1040-NR, U.S. Nonresident Alien Income Tax Return. 

Sample

Visit the IRS website to find out more about filing requirements.

You are also required to file foreign bank and financial accounts (FBAR) that are valued at more than $10,000 combined at any point during the entire year. The IRS goes into great detail about these reports and who must file them.

There are many schedules that go with this type of tax return and report; it is highly recommended you engage an accountant who is familiar with this process.