William de Grey, 1st Baron Walsingham (1763–1845), was a British lawyer and politician. He served as a Member of Parliament for Cambridge and was appointed as a judge in the Court of Common Pleas. His legal career was marked by significant contributions to the British judicial system. In 1831, he was elevated to the peerage as Baron Walsingham, which allowed him to sit in the House of Lords. Throughout his life, de Grey was known for his dedication to public service and his influence in legal reforms during a transformative period in British history.