A sabre (French: [ˈsabʁ], or saber in American English) is a type of backsword with a curved blade associated with the light cavalry of the early modern and Napoleonic periods. Originally associated with Central European cavalry such as the hussars, the sabre became widespread in Western Europe during the Thirty Years' War. Lighter sabres also became popular with infantry of the early 17th century. In the 19th century, models with less curving blades became common and were also used by heavy cavalry.

The military sabre was used as a duelling weapon in academic fencing in the 19th century, giving rise to a discipline of modern sabre fencing (introduced in the 1896 Summer Olympics) loosely based on the characteristics of the historical weapon in that it allows for cuts as well as thrusts.