William Fitzwilliam, 4th Earl Fitzwilliam (1780-1833), was a prominent British nobleman and politician. He inherited the title from his father and became known for his significant contributions to the Whig Party. Fitzwilliam served as a Member of Parliament and held various political positions, advocating for reform and social improvement. Fitzwilliam was also a notable landowner, managing extensive estates in Yorkshire and Ireland. He was involved in agricultural advancements and supported local communities through various initiatives. His legacy includes a commitment to public service and a focus on the welfare of his tenants and the broader society.