The Investment Canada Act (ICA; French: Loi sur Investissement Canada, LIC) is a Canadian federal law governing foreign direct investment in Canada. The ICA was one of the first acts of Brian Mulroney's newly elected Progressive Conservative government, receiving royal assent on 20 June 1985. It has been amended at various times, including recently through Bill C-34, An Act to amend the Investment Canada Act, which received Royal Assent in 2024. Pertinent regulations include the Investment Canada Regulations, SOR/85-611 and the National Security Review of Investments Regulations, SOR/2009-271.

The ICA allows the government to review foreign investments of any size for national security risks, including minority investments and greenfield investments. The ICA also allows the government to review foreign acquisitions of control above a certain dollar threshold to determine whether it is of "net benefit" to Canada. The ICA is largely administered by Innovation, Science and Economic Development Canada (ISED). The Minister of Industry, in consultation with the Minister of Public Safety, is responsible for conducting national security reviews and coordinating with investigative bodies. For investments related to cultural industries, the Department of Canadian Heritage is responsible for the act's administration.

The dollar threshold for net benefit review is updated yearly based on Canada's Gross Domestic Product, and varies depending on whether the investment is a private sector Trade Agreement investment, private sector World Trade Organization (WTO) investment, state-owned-enterprise WTO investment, and non-WTO investment or investment in the cultural sector. As of 2026, the thresholds are as follow:

The Act was intended to signal Canada's openness to foreign investment and coincided with a narrowed mandate of the Foreign Investment Review Agency (FIRA), which was renamed Investment Canada. FIRA had been set up by Pierre Trudeau's Liberal government to limit increasing US ownership of Canadian business. Canadian nationalists criticized FIRA's effectiveness, noting that in practice it was rarely used to actually forbid an investment. The business community and opposition Progressive Conservative Party criticized FIRA for its activism, saying it had stifled investment from the emerging global economy.

All transactions that are acquisitions of a Canadian business by non-Canadians must be "notified" (ICA ss. 11-12), but only those above a 5 million dollar threshold (or 50 million dollars for indirect investments, such as shares) are reviewable (ICA s. 14). If the investor is a WTO member, the threshold was 320 million in 2012.

The Act empowers a Director of Investments which is also the Deputy Minister of Industry , to produce decisions, and reports of decisions. The thresholds, for valuations above which the ICA is to be invoked, are (according to the legislation) several and hinge on whether or not the investors are part of the World Trade Organization.

While the ICA gives Investment Canada the power to restrict investment, its mandate is only to "review...significant investments...in a manner that encourages investment, economic growth and employment opportunities" unless proposed investments specifically injure national security. According to labour economist Jim Stanford, the Mulroney government never invoked the Act to deter a foreign investment, nor did its successors, the Chrétien and Martin Liberal governments.

Foreign investment in Canada rose significantly in the wake of the ICA, from approximately $100 billion in 1985 to over $550 billion in 2006.