Sir Benjamin Lee Guinness, 1st Baronet (November 1, 1798) - (May 19, 1868) was an Irish brewer and philanthropist. Born in Dublin, he was the son of Arthur Guinness, and grandson of the latter's namesake who founded the Guinness brewery. He joined his father in the business at an early age, and in around 1825 took sole control. By 1855, when his father died, Guinness had become the richest man in Ireland, having built up a huge export trade and continually enlarged the brewery.

Elected Lord Mayor of Dublin in 1851, Guinness entered the House of Commons in 1865 as Conservative representative for the City of Dublin. In 1860 he undertook at his own expense the restoration of the city's St Patrick's Cathedral, an enterprise that cost over £150,000. In recognition of his generosity he was created a baronet in 1867, dying the following year at his Park Lane London home. He was succeeded in the baronetcy by his eldest son, Arthur Guinness, 1st Baron Ardilaun, who took over the brewery with his brother, Edward Guinness, 1st Earl of Iveagh.