Sir Thomas Lucas (1598 – before October 1649), was a professional soldier from Lexden, just outside Colchester in Essex, England, who served with the Dutch States Army in the Eighty Years War and later fought in the Irish Confederate Wars. He took no part in the 1648 Second English Civil War, even though his younger brother Charles Lucas (1613–1648) led the Royalist defence of Colchester and was executed after it surrendered. He died sometime before October 1649.