This paper provides an overview and assessment of the international aspects of Canada’s income tax system at the time of Canada’s sesquicentennial. The timing for such a review is particularly appropriate for three main reasons: 2017 was also the 100th anniversary of the Income Tax Act; the international community, including Canada, has recently completed a major overhaul of the international tax rules to prevent base erosion and profit shifting; and, in late 2017, the United States adopted a major tax reform with important changes to its international tax rules. These US changes, including the deep reduction in the US corporate tax rate from 35 to 21 percent, are game-changing for Canada and many other countries, and Canada needs to respond quickly. Neither a primer on Canada’s international tax rules, nor a detailed technical analysis of those rules, this paper takes a broad approach to Canada’s international tax system.