William Fitzwilliam, 5th Earl of Southampton (1783-1854) was a British nobleman and politician. He was born into a prominent family and inherited the title of Earl of Southampton in 1842. Fitzwilliam was known for his involvement in local governance and his contributions to the community, particularly in Hampshire. In addition to his political career, Fitzwilliam was a patron of the arts and supported various cultural initiatives. He was also associated with the Whig Party, which played a significant role in British politics during the 19th century. His legacy includes a commitment to public service and cultural enrichment.