[1] He was educated at Shrewsbury School before going up to Trinity College, Cambridge, where he graduated in 1957 with a Bachelor of Arts (BA) degree in Engineering.

Methuen worked as a design engineer for Westinghouse Brake and Signal Company from 1957 to 1967, and then as a computer systems engineer for IBM UK Ltd from 1968 to 1975 and for Rolls-Royce Holdings plc from 1975 to 1994.

He also voted to block the Marriage (Same Sex Couples) Act 2013.

[2] Lord Methuen married firstly Mary Catherine Jane Hooper in 1958; they divorced in 1993.

He was succeeded in the title by his first cousin once removed, James Methuen-Campbell (born 1952).