James Stewart (– 27 April 1768) was a Scottish soldier and politician.
He was the second son of James Stewart, 5th Earl of Galloway and his wife Lady Catherine Montgomerie, daughter of Alexander Montgomerie, 9th Earl of Eglinton.
He was educated at Eton, and served as an officer in the Scots Guards for over 30 years, becoming a Lieutenant-General in 1758.
He was a member of parliament (MP) in the Parliament of Great Britain for 27 years, representing Wigtown Burghs 1734–41 and 1747–54 and Wigtownshire 1741–47 and 1754–61.
His younger brother William was also an MP for Wigtown Burghs.