This study examines the complexity of Canada’s corporate income tax system from the perspective of multinational corporations and compares it with the complexity of the US system, also taking into account measures of complexity for 19 other member countries of the Organisation for Economic Co-operation and Development (OECD). The author finds that with regard to the Canadian tax code, the most complex laws are those on corporate reorganization, transfer pricing, and controlled foreign corporations, and with regard to the Canadian tax framework, the most complex areas are tax audits, tax-law enactment, and tax guidance. In comparison with other OECD countries, Canada is remarkably similar to the United States. Both countries have a medium level of overall complexity, and both have a more complex tax code but a less complex tax framework than other countries. However, a closer examination of the Canadian and US tax codes and tax frameworks reveals some significant differences in complexity levels, particularly in respect of certain tax laws.