Donald Michael Ellison Foster, Baron Foster of Bath, PC (born 31 March 1947) is a British Liberal Democrat politician who represented Bath, Somerset as its constituency MP from 1992 until 2015.
From October 2013 to May 2015 he held the ex officio title of Comptroller of the Household as Liberal Democrat Chief Whip. He was created Baron Foster of Bath, of Bath in the County of Somerset in the 2015 Dissolution Honours, becoming a member of the House of Lords.
Foster was born in Preston, Lancashire, and attended the Lancaster Royal Grammar School before Keele University where he was awarded a BSc degree in Physics and Psychology in 1969, and also received the CertEd that same year. He later received an MEd in Education at the University of Bath in 1981.
He was a science teacher at Sevenoaks School in Kent in 1969, before appointment as Avon Education Authority's Science Project Director in 1975 and as a Lecturer in Education at Bristol University in 1980, before being engaged as a management consultant with Pannell Kerr Forster from 1989 until his election to the House of Commons.