Colonel Sir Thomas Courtenay Theydon Warner, 1st Baronet CB (19 July 1857 – 15 December 1934) was a British politician, who served as the Member of Parliament (MP) for North Somerset from 1892 to 1895, and for Lichfield from 1896 to 1923. Initially a member of the Liberal Party, he stood at the 1918 general election as a Coalition Liberal, and at the 1922 general election as National Liberal. He was also the first mayor of the Municipal Borough of Walthamstow after its incorporation in 1929. His grave lies in the churchyard of St Mary's, Thorpe Morieux, Suffolk.