Donald Martin Thomas, Baron Thomas of Gresford, OBE, KC (born 13 March 1937) is a British Liberal Democrat politician. Born the son of a Llangollen policeman, he was educated at Grove Park Grammar School, Wrexham, and at Peterhouse, Cambridge, he graduated with an LLB in Law and an MA in Classics. He practised as a solicitor in Wrexham from 1961 to 1966 before becoming a lecturer in law. He was called to the bar at Gray's Inn in 1967, and was appointed a QC in 1979. He became a deputy circuit judge in 1974, a Crown Court Recorder in 1976, and a Deputy High Court judge in 1995.