Thomas Cromwell (; c. 1485 – 28 July 1540), briefly Earl of Essex, was an English lawyer and statesman who served as chief minister to King Henry VIII from 1534 to 1540, when he was beheaded on orders of the king, who later blamed false charges for the execution.

Cromwell was one of the most powerful proponents of the English Reformation, and the creator of true English governance. He helped to engineer an annulment of the king's marriage to Catherine of Aragon so that Henry could lawfully marry Anne Boleyn. Henry failed to obtain the approval of Pope Clement VII for the annulment in 1533, so Parliament endorsed the king's claim to be Supreme Head of the Church of England, giving him the authority to annul his own marriage. Cromwell subsequently charted an evangelical and reformist course for the Church of England from the unique posts of Vicegerent in Spirituals and Vicar-general (the two titles refer to the same position).^{: 658, fn. 2}

During his rise to power, Cromwell made many enemies, including Anne Boleyn, with his fresh ideas and lack of nobility. He duly played a prominent role in her downfall. He later fell from power, after arranging the king's marriage to German princess Anne of Cleves. Cromwell had hoped that the marriage would breathe fresh life into the Reformation in England, but Henry found his new bride unattractive and the marriage was a disaster for Cromwell, ending in an annulment six months later. Cromwell was arraigned under a bill of attainder and executed for treason and heresy on Tower Hill on 28 July 1540. The king later expressed regret at the loss of his chief minister, and his reign never recovered from the incident.