The West Midlands Regiment was a short-lived British Territorial Army regiment from 1999 until it was re-designated as 4th Battalion, Mercian Regiment, in 2007.

The regiment was formed in 1999 by the amalgamation of three territorial infantry battalions: 5th Battalion, Royal Regiment of Fusiliers; 5th Battalion, The Light Infantry; and 3rd Battalion, Staffordshire Regiment.

[1] The regiment was composed of a headquarters company and five rifle companies, continuing to use the insignia of the regular regiments to which they were affiliated.

Its initial structure was as follows:[2][3] Not long prior to re-designation of a battalion of the Mercian Regiment, the regiment absorbed the companies from other regiments that were within the new regiment's recruiting area, in order to ease the re-designation process.

[4] It now serves as the reserve infantry battalion for Cheshire, Staffordshire, Worcestershire, West Midlands, Derbyshire, and Nottinghamshire.