Malik Muhammad Rustam Kayani (Urdu: ملک محمد رستم کیانی), also known as M. R. Kayani or Justice Kayani, (18 October 1902 – 15 November 1962) was a distinguished Pakistani jurist who served as Chief Justice of West Pakistan from 1958 to 1962. He is noted for his opposition to the dictatorship of General Ayub Khan.