Bolingbroke, now called Old Bolingbroke, is a market town near Boston in Lincolnshire, England. It is the site of a historic castle, once owned by John of Gaunt.

King Henry IV of England, who was born at Bolingbroke Castle, is often referred to simply as "Bolingbroke". Henry St John, Viscount Bolingbroke is also sometimes referred to simply by his title.