Thomas Walker (1749–1817) was an English cotton merchant and political radical.
He was the son of Thomas Walker, a merchant in Bristol who moved to Manchester. An early influence was the teaching of James Burgh. He became a Manchester cotton merchant himself. He had a town house and warehouse on South Parade, adjacent to St Mary's Church, Manchester, and a country place at Barlow Hall, rented from William Egerton.
In 1784 Walker led the successful local opposition to William Pitt's fustian tax. With Thomas Richardson, he testified to the Board of Trade committee in London in January 1785. After some confusion during the spring, the House of Commons voted to repeal the tax in April, and the Manchester men returned north as heroes. The same year he founded the General Chamber of Manufactures, set up to lobby against Pitt's measures on trade with Ireland.
In 1787 Walker opposed the Eden Treaty, a divisive position. In 1788, at a meeting of fustian manufacturers and calico printers about the East India Company, Robert Peel spoke, and the unpopular Walker clashed physically with his brother Laurence.
Walker was well connected, through business, religious, political and family networks. Himself an Anglican of latitudinarian views, he supported the campaign against the religious disabilities of dissenters, and was a founder member of the Unitarian Society set up by Theophilus Lindsey. He took to heart comments of John Jebb that Pitt, after Lord North, was the most dangerous politician in the country. He married into the Shore family of Sheffield: Samuel Shore (1738–1828), his brother-in-law, was an ironmaster, dissenter, and activist of the Yorkshire Association.