Switzman v Elbling and A.G. of Quebec, [1957] SCR 285 is a Supreme Court of Canada decision in which the Court ruled that Quebec's Act to Protect the Province Against Communistic Propaganda, commonly known as the "Padlock Law", was ultra vires of the provincial legislature.

[2] Rand, Kellock, and Abbott JJ further held that the law was ultra vires because it violated freedom of expression guaranteed under an implied bill of rights springing from the "democratic form of government established in Canada", but this view was not shared by the rest of the majority.

In February 1948, Bailey, a former Montreal City Councillor and a Communist himself, wanted to assign his apartment to John Switzman, a prominent Marxist who wanted to turn the apartment into a local Communist hub.

Freda Elbling, the landlord, tried to prevent Switzman from taking the apartment for fear of having her building appropriated by the province under the Padlock Law.

[5] In an 8 to 1 decision, the Supreme Court found that the law was ultra vires and it was struck down.