John Louis Engdahl (November 11, 1884 – November 21, 1932) was an American socialist journalist and newspaper editor. One of the leading journalists of the Socialist Party of America, Engdahl joined the Communist movement in 1921 and continued to employ his talents in that organization as the first editor of The Daily Worker. Engdahl was also a key leader of the International Red Aid (MOPR) organization based in Moscow, where he died in 1932.