James MacLagan or McLagan (1728–1805) was a Church of Scotland minister and writer. He was chaplain to the 42nd (Black Watch) Regiment, 1764–1781, including preaching in Gaelic and English at the garrison at Fort Pitt (Pennsylvania), then minister in Amulree. He married the daughter of the translator of the New Testament in Gaelic, James Stuart of Killin. He was author of Spiritual views of the divine government 1831 and other works and corresponded with James Macpherson, and was one of Macpherson's sources for the Ossian poems.
- History of Pittsburgh and environs George Thornton Fleming, American Historical Company, American historical society, incorporated, New York – 1922 "They waited on the commander of the fort, Captain William Murray,[disambiguation needed] who received them politely and introduced them to the Rev. Mr. McLagan, the chaplain of the 42d Highlanders, then the garrison of the fort."
- James McLagan, Society in Scotland for Propagating Christian Knowledge – 1831
- Bailey Saunders The Life and Letters of James Macpherson 1969 – Page 146 "Some of his letters to a Mr. James McLagan, minister of Amulrie in Perthshire"
- The Genuine Remains of Ossia, literally translated 1841 Page 7 "James MacLagan, then minister of Amulree, in which he requests that Mr MacLagan would do him the favour of transmitting to him his collection of ancient poems; and informs him that he intended visiting Mull and the coast of Argyle, "