The Buffs (Royal East Kent Regiment), formerly the 3rd Regiment of Foot, was a line infantry regiment of the British Army traditionally raised in the English county of Kent and garrisoned at Canterbury. It had a history dating back to 1572 and was one of the oldest regiments in the British Army, being third in order of precedence (ranked as the 3rd Regiment of the line). The regiment provided distinguished service over a period of almost four hundred years accumulating one hundred and sixteen battle honours. In 1881, under the Childers Reforms, it was known as the Buffs (East Kent Regiment) and later, on 3 June 1935, was renamed the Buffs (Royal East Kent Regiment).

In 1961, it was amalgamated with the Queen's Own Royal West Kent Regiment to form the Queen's Own Buffs, The Royal Kent Regiment, which was later merged, on 31 December 1966, with the Queen's Royal Surrey Regiment, the Royal Sussex Regiment and the Middlesex Regiment (Duke of Cambridge's Own) to form the Queen's Regiment. This regiment was, in turn, amalgamated with the Royal Hampshire Regiment, in September 1992, to create the Princess of Wales's Royal Regiment (Queen's and Royal Hampshires).