Robert F. Hagan is an American politician of the Democratic party who holds a seat in the Ohio State Senate. He has been chosen by the Senate Democratic caucus to serve as assistant minority whip in the 126th Ohio General Assembly.

Before entering electoral politics, for 15 years Hagan worked as a locomotive engineer for CSX Transportation.

In 1986, Hagan was elected to a seat in the Ohio House of Representatives, representing the 53rd Ohio House district, centered on Youngstown, Ohio. At the time, his father, Robert E. Hagan, was also serving in the House. This period, from 1986 to 1990, was the first time that a father and a son simultaneously held seats in the Ohio House of Representatives. He served in the House for 10 years. Hagan was appointed to the state senate on Feb. 12, 1997, to represent the 33rd district in northeastern Ohio, centered on the city of Alliance, Ohio.

Hagan's brother, Timothy Hagan, served for many years as a county commissioner in Cuyahoga County, Ohio. In 2002, Tim Hagan was the Democratic nominee for the office of Governor of Ohio.