James Buchanan (1791–1868) was a U.S. Senator from Pennsylvania from 1834 to 1845. Senator Buchanan may also refer to:
Andrew Buchanan (American politician) (1780–1848), Pennsylvania State Senate Benjamin Franklin Buchanan (1857–1932), Virginia State Senate Brian Buchanan (politician) (fl. 2010s–2020s), Indiana State Senate Hugh Buchanan (politician) (1823–1890), Georgia State Senate J. W. Buchanan (1869–1941), Arizona State Senate John C. Buchanan (Virginia politician) (1911–1991), Virginia State Senate John Preston Buchanan (1888–1937), Virginia State Senate