The 19th Mounted Brigade previously known as the 2/1st Scottish Horse Mounted Brigade was a second line yeomanry brigade of the British Army during the First World War. Raised after the declaration of war, it was a mirror formation of the first line Scottish Horse Mounted Brigade. It had under command the 2/1st Scottish Horse, the 2/2nd Scottish Horse and the 2/3rd Scottish Horse. All of which were converted in cyclist units in 1916, the brigade, never having seen any active service, ceased to exist.