The Texas Cavalry Service Medal was a military decoration of the Texas National Guard which was created by an act on the United States Congress on April 16, 1924. The decoration was intended to recognize the service of the Texas cavalry which had performed Mexican border patrol duty during the years of the First World War.

The Texas Cavalry Service Medal was awarded to members of the first two brigades of the Texas National Guard cavalry who were federalized for United States Army service in 1917. Qualifying dates of the Texas Cavalry Service Medal are from December 8, 1917 to November 11, 1918.

Since the Texas Cavalry Service Medal was created by Congress to commemorate federal service, the award has a dual status as both a federal military decoration and an award of the National Guard. For this reason, the Texas Cavalry Service Medal was authorized for wear on active duty United States military uniforms, yet did not appear as an authorized decoration in Army regulations.