Jonas Hartzell McGowan (April 2, 1837 – July 5, 1909) was a politician from the U.S. state of Michigan. McGowan was born in Smith Township, Ohio (then part of Columbiana County, now Mahoning County). He was the eighth of ten children of Samuel and Susan McGowan. His paternal Scotch-Irish ancestors had fled religious persecution and settled in Pennsylvania. His father was a pioneer in Columbiana County, Ohio, where he cleared a tract of government land and occupied it as a homestead. In 1854, Samuel moved his family to Orland, Indiana, where he died in 1860. McGowan's mother was of German descent and survived the father for another four years. McGowan's father was an abolitionist and his house served as a depot on the Underground Railroad.