Michael Keith Smith (1953 – 3 July 2010), commonly known as Mike Smith, was the founder-chairman of the Conservative Democratic Alliance, a British right-wing pressure group. He was also the successful claimant in Keith-Smith v Williams, a landmark English libel case in 2006 that confirmed that existing libel laws applied to internet discussion. Smith died after jumping from the keep at Portchester Castle on 3 July 2010.