Richard was the third and youngest son of the Rt. Hon. Robert Arthur James Cecil, K.G., P.C., Viscount Cranborne, and his wife, Elizabeth Vere Cavendish. His father succeeded as 5th Marquess of Salisbury.  He was born at Hatfield House, the residence of his grandparents.

He was educated at Eton and matriculated in 1941. He was up at Christ Church for a year.

He was a Sergeant Trainee Pilot in the Royal Air Force Volunteer Reserve when he died, accidentally, on 12 August 1944.

He is buried in the churchyard of Saints Mary & Bartholomew at Cranborne, Dorset where his family lived.

An anonymous memorial to him in The Times on 13 August 1945 said

“Thou wast the Morning Star among the living
Ere thy fair light had fled
Now having died, thou art as Hesper, giving
New splendour to the dead.”