The Royal College of Elizabeth, better known as Elizabeth College, is a co-educational independent school in Saint Peter Port, Guernsey. A member of the HMC (The Heads' Conference), it is a public school in the sense of the term used in England and Wales. Founded on 25 May 1563 by royal charter from Elizabeth I, it is one of the oldest schools in the British Isles and the oldest public school in the Channel Islands.

The school endured a turbulent two and a half centuries after its foundation, with several principals being dismissed or resigning following disputes with the local authorities. In 1824, it was re-chartered with new staff and an improved curriculum to attract fee-paying pupils from England. During the German occupation of the Channel Islands, the school was evacuated to Great Hucklow, Derbyshire. Having been a boarding school since its foundation, the decline in the number of pupils admitted as boarders following the world war period meant the school became a day school in 1996. The school became co-educational in 2021.

The school teaches around 570 pupils aged 11 to 18. As a selective school, prospective pupils must pass an entrance exam to be offered a place, although the school accepts pupils from a wide ability range. The school charges £5,216 per term, with three terms per academic year, (or £15,648 per annum) as of 2024/2025. There is an associated junior school for ages 2½ to 11 on adjoining sites at the nearby Acorn House (pre-school), in King's Road, and Beechwood (primary school), in Queen's Road.

Alumni of the school are known as Old Elizabethans. Since 1824, pupils have been allocated a unique, sequential school number. Among these alumni are multiple Olympians, several Bailiffs of Guernsey and other notable persons. Noted in the nineteenth and early-twentieth centuries for producing students who later joined military colleges in the UK, the school's alumni includes four Victoria Cross recipients.

In the mid-sixteenth century, the Queen's Commissioners raised concern over the civil, political and religious administration of Guernsey. In the year the school was founded, three people were burned for witchcraft. The Privy Council thought, therefore, that the island required secondary education in the hope that students might go on to preach as clergymen on the island in line with principles of the Protestant Reformation. They recommended the establishment of a school by royal charter, whereby a free grammar school would be founded by the States of Guernsey with a master appointed by the island's Governor. The school was founded on 25 May 1563 as Queen Elizabeth's Grammar School by a patent roll from Elizabeth I which read:

Also since there is no grammar school in the isle, to erect a free grammar school there called Queen Elizabeth's Grammar School under the seal of the isle; the schoolmaster thereof to be appointed and removable by the Captain (except the Queen shall otherwise order); the school to be endowed with wheat rentes of 80 quarters a year found to belong to the Queen by the late Commissioners.

It was the fourth school to be established on the island. To create a site for the school, Franciscan friars were moved from land at La Rue Des Frères. The first schoolmaster was Belgian scholar, Adrian Saravia. Saravia left the island by 1571, describing the local population as an "uncivilised race" which "hates all learning". Over the next two and a half centuries the school struggled to survive, in large part due to shortcomings with the statutes on which the school was founded: the raising of funds was a near-constant issue, with buildings being abandoned and land alienated; principals (then known as masters) came and went; the pupil roll never exceeded 29 and, for several periods, there were no students at the school at all.

In 1824, due to increased demand for a higher standard of local education, including at the school, the island's Lieutenant Governor, John Colborne, established a committee to review the school. It was re-chartered that year, and on 19 October 1826 the foundation stone of a new school building to be designed John Wilson was laid by Colborne and the school was renamed the Royal College of Elizabeth. The reform introduced a register of pupils, whereby pupils are allocated a unique, sequential school number.