The Gloucestershire Regiment was an infantry regiment of the British Army. Nicknamed "The Glorious Glosters", the regiment carried more battle honours on their Regimental colours than any other British Army line regiment.

The origins of the regiment lie in the regiment formed in Portsmouth in 1694 by Colonel John Gibson. This was named the 28th Regiment of Foot in 1751 and renamed the 28th (North Gloucestershire) Regiment of Foot in 1782. After the Childers reforms, the regiment amalgamated with the 61st (South Gloucestershire) Regiment of Foot to form the two-battalion Gloucestershire Regiment on 1 July 1881.

The regiment amalgamated with the Duke of Edinburgh's Royal Regiment in 1994 to form the 1st Battalion, The Royal Gloucestershire, Berkshire and Wiltshire Regiment.

In March 2005, it was announced that this regiment would merge with the Light Infantry, The Royal Green Jackets and the Devonshire and Dorset Regiment to form the 1st Battalion, The Rifles. At this time, the RGBW was made a light infantry regiment, becoming the RGBWLI. This served to forge identity within the new Rifles regiment.