Old Buck

Old Buck may refer to:


 * Nickname of James Buchanan (1791–1868), fifteenth president of the United States
 * Nickname of Robert C. Buchanan (1811–1878), Union Army general during the American Civil War
 * A Finnish malt whisky made by Panimoravintola Beer Hunter's
 * Old Buck, a horse owned by Abraham Lincoln when he was a lawyer in Springfield, Illinois; see Old Bob, Old Buck's replacement