The Royal Berkshire Regiment (Princess Charlotte of Wales's) was a line infantry regiment of the British Army in existence from 1881 until 1959. The regiment was created in 1881, as the Princess Charlotte of Wales's (Royal Berkshire Regiment), by the amalgamation of the 49th (Princess Charlotte of Wales's) (Hertfordshire) Regiment of Foot and the 66th (Berkshire) Regiment of Foot.
In 1921, it was renamed the Royal Berkshire Regiment (Princess Charlotte of Wales's).
On 9 June 1959, the Royal Berkshire Regiment (Princess Charlotte of Wales's) was amalgamated with the Wiltshire Regiment (Duke of Edinburgh's) to form the Duke of Edinburgh's Royal Regiment (Berkshire and Wiltshire).