Joseph Rosier (January 24, 1870 – October 7, 1951) was a United States Senator from West Virginia. Born in Wilsonburg, West Virginia, he attended the public schools and graduated from Salem College in 1895. In 1890, Rosier was a teacher of the village school at Bristol, West Virginia and was principal of the public schools of Salem in 1891 and 1892; in 1893 and 1894 he was superintendent of schools of Harrison County, West Virginia and was a member of the faculty of Salem College from 1894 to 1896. He was a teacher in the State normal school at Glenville, West Virginia from 1896 to 1897 and was a member of the faculty of the State Teachers' College at Fairmont, West Virginia from 1897 to 1900. He was superintendent of schools of Fairmont from 1900–1915 and was president of Fairmont State College, Fairmont from 1915–1945 and then president emeritus.