The desire of the citizens of Gibraltar to defend their City and to serve side by side with the rest of the Garrison dates back to 1704 when the Rock was captured by the British. In 1755 an organised body of local men known as the 'Genoese Guard' mounted pickets at the land frontier and other points.

During the Great Siege (1779-1783) some 160 local residents volunteered to assist in the Great Sortie (27th November 1781), which under the command of General George Augustus Elliot, the then Governor and later Baron Heathfield of Gibraltar, destroyed the enemy lines.

The forefathers of the present Regiment can be said to be the Gibraltar Volunteer Corps. It was shortly after the outbreak of war in 1914, that a group of Gibraltarians assembled at the Calpe Rowing Club, pledged themselves to take up arms as citizen soldiers to fight for King and Country. During the Great War the Corps provided a substantial reinforcement to assist in the defence of the Rock. The Corps was disbanded in 1919 when hostilities had ceased.

Twenty years later, on the 28th April 1939, the Gibraltar Defence Force was raised under the Governorship of General Sir Edmund Ironside. From the outbreak of the war in September 1939, the Gibraltar Defence Force served side by side with the regular units of the Garrison. The force consisted of anti-aircraft and coast artillery; motor transport; signals; medical; fire-fighting and special constabulary sub-units. It saw action against Italian and Vichy French aircraft on numerous occasions, shooting down its first enemy aircraft in August 1940.

Following the policy in the United Kingdom conscription was retained in Gibraltar after the war. In 1945 the main body that served during the war was demobilised and a small permanent cadre was retained to train the conscripts. The young men of Gibraltar were required to undertake six months (later reduced to four months) compulsory military basic training. After their basic training, they were placed on the reserve. Reservists were then required to undergo two weeks training on alternate years up to the age of twenty-eight.

In 1958 the permanent cadre of the Gibraltar Defence Force and the Reserve together with a recently formed Volunteer Reserve of Officers, Warrant Officers and Non Commissioned Officers, were formed into the Gibraltar Regiment. The Regiment, having a dual role, was organised as an infantry battalion with four rifle companies and a gunner troop. The latter was given the task of manning the 9.2-inch coastal guns. This organisation remained in force until 1971.

In 1971 HM The Queen approved the granting of the first ever Colours to the Regiment. The Colours were presented on the 25th September 1971 and on that same day the Regiment was also granted the Freedom of the City of Gibraltar.

In 1971 conscription ended and from the 7th October 1971 when the last conscript departed to the 315t March 1991, the Regiment was manned by Volunteer Officers and Soldiers assisted by a small permanent cadre. During most of that time the Regiment consisted of a rifle company, an artillery battery (Thomson's Battery) and an air defence troop.

With the withdrawal of the regular infantry battalion in April 1991, the Regiment was reorganised into an all infantry unit and it assumed the role of the major army unit in Gibraltar. The Regiment now consists of an headquarter company (Thomson's Battery) and three rifle companies manned by regular and Territorial Army soldiers. The Regiment also has a Band and a Corps of Drums.

The Regiment is allied to the Royal Regiment of Artillery, the Royal Anglian Regiment, the Corps of Royal Engineers and the Royal Irish Regiment.