Herbert Robin Cayzer, 3rd Baron Rotherwick (born 12 March 1954), is a British landowner and estate manager.

He is the son of Herbert Cayzer, 2nd Baron Rotherwick (1912-1996), chairman of Caledonia Investments and British and Commonwealth Shipping and a Major of the Royal Scots Guards during the Second World War,[3] and Sarah Jane (1933-1978), daughter of Sir Michael Nial Slade, 6th Baronet.

A qualified pilot, he represented the Popular Flying Association as a member of the executive committee from 1997 to 2001, and as vice-chairman from 1999 to 2001.

The passing of the House of Lords Act 1999 saw him elected as one of the 92 hereditary peers to remain in their seats for life.

His areas of interest are listed as agriculture, animals, food and rural affairs; aviation; defence; energy and environment.