Saxe-Coburg-Saalfeld was one of the Saxon Duchies held by the Ernestine line of the Wettin Dynasty. Established in 1699, the Saxe-Coburg-Saalfield line lasted until the reshuffle of the Ernestine territories that occurred following the extinction of the Saxe-Gotha line in 1825, in which the Saxe-Coburg-Saalfeld line received Gotha, but lost Saalfeld to Saxe-Meiningen.

The Ernestine duchies, also known as the Saxon duchies, were a group of small states whose number varied, which were largely located in the present-day German state of Thuringia and governed by dukes of the Ernestine line of the House of Wettin.