Baron Clitheroe of Downham in the County of Lancaster is a title in the Peerage of the United Kingdom.

It was created in the 1955 Birthday Honours for the Conservative politician Ralph Assheton, who had previously served as Financial Secretary to the Treasury.

[3] He was the son of Ralph Cockayne Assheton, for many years a member of the Lancashire County Council, who had been created baronet of Downham in the County of Lancaster, on 4 September 1945.

Three months after being raised to the peerage, Lord Clitheroe succeeded his father in the baronetcy.

[2] In the immediate aftermath of World War II, Ralph Assheton also acquired title to the manorial and mineral rights as well as land holdings within the former Honour of Clitheroe.