The Grenadier Guards (GREN GDS) is an infantry regiment of the British Army. It is the most senior regiment of the Guards Division and, as such, is the most senior regiment of infantry. It is not, however, the most senior regiment of the Army, this position being attributed to the Life Guards. Although the Coldstream Guards was formed before the Grenadier Guards, that regiment is ranked after the Grenadiers in seniority as it was a regiment of the New Model Army.

The Grenadier Guards traces its lineage back to 1656, when Lord Wentworth's Regiment was raised in Bruges, in the Spanish Netherlands (current-day Belgium), where it formed a part of exiled King Charles II's bodyguard. A few years later, a similar regiment known as John Russell's Regiment of Guards was formed.  In 1665, these two regiments were combined to form the 1st Regiment of Foot Guards. Since then the Grenadier Guards have served ten Kings and three Queens, including currently Queen Elizabeth II.

In 1994, under the Options for Change reforms, the Grenadier Guards was reduced to a single battalion. The 2nd Battalion was put into 'suspended animation', and its colours passed for safekeeping to a newly formed independent company, which was named "The Nijmegen Company As a result of this the regiment was reduced to its current composition: one full battalion, the 1st Battalion, consisting of three rifle companies, a support company and a headquarters company, based at Wellington Barracks, London, and one independent company, The Nijmegen Company.