John Montagu, 3rd Earl of Salisbury (c. 1680–1744), was a British nobleman and politician. He was a member of the Montagu family and succeeded his father as the Earl in 1705. Montagu served in various political roles, including as a Member of Parliament and later as a Lord of the Treasury. He was known for his involvement in the Whig party and played a significant role in the political landscape of his time. Montagu was also a patron of the arts and contributed to the cultural life of England during the early 18th century.