Sir John Benn Walsh, 1st Baronet (10 February 1759 – 7 June 1825) was an English landowner and MP.
He was born in Cumberland as John Benn, the only son of William Benn of Moor Row, Whitehaven, Cumberland and his wife Mary, daughter of Timothy Nicholson. In 1787 he married Margaret, daughter of Joseph Fowke of Kent. In 1795 his wife inherited the Indian-made fortune of her mother's brother Sir John Walsh on condition that they changed the family name to Walsh, which they duly did, by Royal Licence. The legacy included Warfield Park, Berkshire, the Radnorshire manors of Cefnllys and Coed Swydd and a number of farms in eastern Radnorshire.
Benn worked for the East India Company in Benares, India as an assistant and secretary to his brother-in-law, Francis Fowke, making a small fortune in the process, which he invested in land to enlarge the family estates, making his family seat at Warfield.
He served as High Sheriff of Radnorshire in 1798 and sat as an MP for Bletchingley, Surrey from 1802 to 1804. He was made a baronet in 1804.
He died in 1825 and was succeeded by his son John, the future Lord Ormathwaite.