James Duncan McGregor (August 29, 1860 – March 15, 1935) was a Canadian agricultural pioneer and officeholder. He served as the 11th Lieutenant Governor of Manitoba between 1929 and 1934. McGregor was born in Amherstburg, Canada West (now Ontario), and was educated at public schools in Windsor but did not attend college. He moved to Manitoba in 1877, and worked in his father's cattle business in Brandon.