Thomas Fitzwilliam, 3rd Earl of Southampton (1600-1643), was an English nobleman and politician. He was born into a prominent family and inherited the title from his father, Thomas Fitzwilliam, 2nd Earl of Southampton. The 3rd Earl was known for his involvement in the English Civil War, where he initially supported the Royalists but later aligned with the Parliamentarians. Throughout his life, the 3rd Earl was also recognized for his contributions to the arts and culture of his time. He was a patron of notable figures, including the playwright William Shakespeare, and played a significant role in the social and political landscape of 17th-century England.