Responsibility for enforcement of the Competition Act rests primarily with four actors: the Commissioner of Competition, the Attorney General of Canada, the Competition Tribunal and the courts. Section 36 of the Act also creates a private right of action, thereby vesting individuals with the ability to recover damages suffered as a result of conduct that is contrary to certain sections of the Competition Act.

The Commissioner heads the Competition Bureau and is Canada's lead competition enforcement official. The Commissioner, supported by the Bureau, investigates criminal matters (e.g., conspiracy, bid rigging, price discrimination, predatory pricing, promotional allowances, resale price maintenance and deceptive marketing practices) and reviewable matters (e.g., refusal to deal, exclusive dealing, market restriction, tying, abuse of dominant position, merger challenges and deceptive marketing practices) under the Competition Act. Criminal matters are ultimately prosecuted by the Attorney General on recommendation of the Commissioner. In the case of reviewable matters, the Commissioner and private parties in some cases may apply to the Competition Tribunal for a remedial order.

Recommending prosecutions to the Attorney General or bringing applications before the Competition Tribunal are not the only means available to the Commissioner for resolving potential violations of the Competition Act. For example, the Commissioner may be satisfied with remedying relatively minor or doubtful violations of the Competition Act on the basis of corrective action. Alternatively, particularly in the case of reviewable matters, the Commissioner may obtain a written undertaking from a party rather than seek a formal remedial order. In the criminal context, the Commissioner may recommend that the Attorney General grant immunity or seek a lesser penalty in certain circumstances, in accordance with the Commissioner's Immunity Program.