The 1st South Midland Mounted Brigade (later numbered as the 5th Mounted Brigade) was a yeomanry brigade of the British Army, formed as part of the Territorial Force in 1908. It served dismounted in the Gallipoli Campaign before being remounted to serve in the Sinai and Palestine Campaign in World War I. In April 1918, it was merged with elements of the 3rd (Ambala) Cavalry Brigade to form 13th Cavalry Brigade. It remained in Palestine after the end of the war on occupation duties.