Gamaliel Bailey (December 3, 1807 - June 5, 1859) was a U.S. journalist. Born at Mount Holly, New Jersey, he graduated from the Jefferson Medical College, Philadelphia, in 1827.
After editing for a short time a religious journal, the Methodist Protestant, at Baltimore, he moved in 1831 to Cincinnati, Ohio, where at first he devoted himself almost exclusively to the practice of medicine. He was also a lecturer on physiology at the Lane Theological Seminary, and at the time of the Lane Seminary debates (February 1834) between the pro-slavery and the anti-slavery students, and the subsequent withdrawal of the latter, he became an ardent abolitionist.
In 1836 he joined James G. Birney in the editorial control of the Philanthropist; in the following year he succeeded Birney as editor, and conducted the paper until 1847 in spite of threats and acts of violence — the printing-office of the Philanthropist was wrecked three times by mobs.
From 1843 also he edited a daily paper, the Herald, and in 1847 assumed control of the new abolitionist publication, the National Era, at Washington, D.C. Here also his paper was the object of attack by pro-slavery mobs, one of which besieged the editor and printers in their office for three days in 1848. This paper had a considerable circulation, and in it, in 1851—1852, Harriet Beecher Stowe's Uncle Tom's Cabin was first published.
Bailey died at sea in the course of a trip to Europe.