Clench is a surname. Notable people with the surname include:
Andrew Clench (died 1692), English physician Jim Clench (1949–2010), Canadian musician John Clench (died 1607), English judge Nora Clench (1867–1938), Canadian violinist Ralfe Clench ( – 1828), farmer, judge and political figure in Upper Canada William J. Clench (1897–1984), American malacologist