The Colonial Laws Validity Act 1865 (28 & 29 Vict. c. 63) is an Act of the Parliament of the United Kingdom. Its long title is “An Act to remove Doubts as to the Validity of Colonial Laws”.
The purpose of the Act was to remove any apparent inconsistency between colonial and Imperial legislation. Thus it confirmed that colonial legislation, provided it had been passed in the proper manner, was to have full effect within the colony, limited only to the extent that it was not in contradiction with any Act of Parliament that contained powers which extended beyond the boundaries of the United Kingdom to include that colony. This had the effect of clarifying and strengthening the position of colonial legislatures, while at the same time restating their ultimate subordination to the Westminster Parliament.
Until the passage of the Act, a number of colonial statutes had been struck down by local judges on the grounds of repugnancy to English laws, whether or not those English laws had been intended by Parliament to be effective in the colony. This had been a particular problem for the government in South Australia, where Justice Benjamin Boothby had struck down local statutes on numerous occasions in the colony’s Supreme Court.
By the mid-1920s, the British government accepted that the dominions should have full legislative autonomy. Accordingly, the imperial Parliament passed the Statute of Westminster 1931, which repealed the application of the Colonial Laws Validity Act 1865 to the dominions (i.e., Australia, Canada, the Irish Free State, New Zealand, Newfoundland, and the Union of South Africa).
The Statute of Westminster 1931 took effect immediately in Canada, the Irish Free State and South Africa. Australia adopted the Statute in 1942 with the passing of the Statute of Westminster Adoption Act 1942, with retroactive effect to 3 September 1939, the start of World War II. The Colonial Laws Validity Act 1865 continued to have application in individual Australian states until the Australia Act 1986 came into effect in 1986.