Thomas Lucas (Royalist)

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.

The eldest son of a prominent Essex family, Lucas took up a military career after being excluded from inheriting the family estates due to his illegitimacy. He took part in the 1639 to 1640 Bishops' Wars and was subsequently made General of Horse in Ireland. After the Irish Rebellion broke out in October 1641, James Butler, 1st Duke of Ormond, appointed him to the Privy Council of Ireland.

Both his brothers served with the Royalist army during the First English Civil War but Lucas remained in Ireland and helped negotiate the September 1643 Ceasefire or "Cessation" with the Irish Catholic Confederacy, which allowed Protestant Irish troops to be transferred to England. Shortly after Charles I surrendered in June 1646, he returned to England and retired to his estates in Lexden after paying a fine.

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.