Raja Rao Birender Singh (20 February 1921 – 30 September 2009) was a King of erstwhile state of Haryana and an Indian politician. He served first as a minister in the state government of Punjab and then as Chief Minister of Haryana from 24 March 1967 - 2 November 1967, and also served as a minister in Punjab state, Haryana state and the Union cabinet. He also served as the second speaker (first male speaker) of Haryana state assembly in 1967. He coined an Indian political vocabulary Aya Ram, Gaya Ram to describe the practice of frequently floor-crossing by legislature.