The Canada Industrial Relations Board is an independent, representational, quasi‑judicial tribunal responsible for the interpretation and application of the Canada Labour Code, Part I (Industrial Relations) and certain provisions of Part II (Occupational Health and Safety).

It was established on January 1, 1999 with the coming into force of Bill C-19, an Act to amend the Canada Labour Code (Part I), R.S. 1998 C. 26, replacing the Canada Labour Relations Board. The amending Act also made significant changes to Part I of the Canada Labour Code in an effort to modernize it and improve the collective bargaining process for federally regulated industries. Before the 1999 amendments, Part I of the Code had remained virtually unchanged since 1972.