The Constitution Act, 1871 (UK), 34 & 35 Vict, c 28, is an Act of the Parliament of the United Kingdom that forms part of the Constitution of Canada.

Section 2 has likely been replaced by paragraph 42(1)(e) of the Constitution Act, 1982, which provides that an amendment to the Constitution of Canada under the general amending procedure is required to establish a new province "notwithstanding any existing law or practice".

Section 3 provides that the Parliament of Canada "may from time to time, with the consent of the Legislature of any Province of the said Dominion, increase, diminish, or otherwise alter the limits of such Province, upon such terms and conditions as may be agreed upon to by the said Legislature, and may, with the like consent, make provision respecting the effect and operation of any such increase or diminution or alteration of territory in relation to any Province affected thereby".

[4] Section 55 of the Constitution Act, 1982 requires the Minister of Justice to prepare a translation of the Act and that it be brought forward for enactment.

Although a translation was prepared in 1990, it has not been brought forward for enactment.