The son of Chidamber N. Chitnis and Lucia Mallik, he was born in London and educated at Stonyhurst College.
An administration assistant of the National Coal Board from 1958 to 1959, Chitnis acted as agent for Eric Lubbock in the successful Liberal campaign in the 1962 Orpington by-election.
Chitnis next worked for the Joseph Rowntree Social Service Trust, as secretary from 1969 to 1975, and chief executive and director from 1975 to 1988.
Chitnis served as an advisor to David Steel during the latter's leadership of the Liberal Party, and was influential during the Lib-Lab pact and the negotiations that led to the SDP–Liberal Alliance.
On 18 July 1977, he was made a life peer as Baron Chitnis, of Ryedale in the County of North Yorkshire.