Section 90 of the Constitution Act, 1867

Royal Proclamation which brought the Act into force on July 1, 1867

Section 90 of the Constitution Act, 1867 (French: article 90 de la Loi constitutionnelle de 1867) is a provision of the Constitution of Canada relating to provincial appropriation and taxation bills, the recommendation for money votes in provincial legislative assemblies, and the federal government's power of disallowance and reservation with respect to provincial laws.

The Constitution Act, 1867 is the constitutional statute which established Canada. Originally named the British North America Act, 1867, the Act continues to be the foundational statute for the Constitution of Canada, although it has been amended many times since 1867. It is now recognised as part of the supreme law of Canada.