Nelson College is the oldest state secondary school in New Zealand, a feat achieved in part thanks to its original inception as a private school.^[2] It is an all-boys school in the City of Nelson that teaches from years 9 to 13. In addition, it runs a private preparatory school for year 7 and 8 boys. The school also has places for boarders, who live in two boarding houses adjacent to the main school buildings on the same campus.

A Nelson College old boy, Charles Monro, was instrumental in introducing the game of rugby into New Zealand.^[3][4]

The school opened with eight students on 7 April 1856 in premises in Trafalgar Square, Nelson, but shortly thereafter moved to a site in Manuka Street. In 1861, the school moved again to its current site in Waimea Road. The Deed of Foundation was signed in 1857 and set out the curriculum to be followed by the college. It included English language and literature, one or more modern languages, geography, mathematics, classics, history, drawing, music and such other branches of science as the Council of Governors should determine.^[5] The Deed stated that the purpose of the school was the "advancement of religion and morality, and the promotion of useful knowledge, by offering to the youth of the Province general education of a superior character."

In 1858, the General Assembly passed the Nelson College Act, which confirmed the status of the school. There were nine initial trustees, including Charles Elliott, David Monro, John Barnicoat, Charles Bigg Wither, William Wells, and Alfred Domett.^[6] In that same year, Alfred Fell gifted the common seal, containing the college's badge and motto, "Pietas, Probitas et Sapientia" (Loyalty, honesty and wisdom).^[5] A team from Nelson College took part in the first game of rugby played in New Zealand, against the Nelson Rugby Football Club on 14 May 1870 at what is now known as the Botanic Reserve, Nelson, and, in 1876, the first inter-College rugby match in New Zealand was played between Nelson College and Wellington College.^[5]

On 7 December 1904, the College was almost completely destroyed by fire. The main building, designed by William Beatson, was said to be a "miniature of Eton," the architect being an old Etonian.^[7] In 1926, Nelson College was invited to join the annual rugby tournament between Christ's College, Wanganui Collegiate School and Wellington College, known as the "Quadrangular".^[5] In the 1929 Murchison earthquake, the main building of the College was once again severely damaged, although only two boys were injured.^[5]

In 2011, Nelson College became the first all-boys college in New Zealand to form a gay-straight alliance support group.^[8] The alliance operated from its own room. In 2017, the group was re-formed, after a failed attempt in 2015.

In 2019, long-serving and retiring headmaster Gary O'Shea claimed that the school needed more girls to stay up-to-date.^[9]

The college has a house system with, as of 16 May 2019,^[update] six different houses that compete across a range of sporting codes, including cross country running and swimming, together with varied cultural activities:

• Barnicoat–Rutherford combined (white & black)
• Chaytor (red)
• Domett (green)
• Monro (blue)
• Robinson (orange)
• Kahurangi (yellow)

The two boarding houses, Rutherford and Barnicoat, recently underwent a five-year refurbishment.^[10] A third boarding house, Fell, was closed to boarders at the end of 2018, and is now available for lease, predominantly to sports and community groups.

• Gilbert Archey, zoologist, museum director, ethnologist
• Phil Costley, athlete
• Edmond de Montalk, language teacher, storekeeper
• Andrew Goodman, rugby union player
• John Gully, artist
• Wilfrid Nelson Isaac, jeweller, art school director
• Frank Milner, school principal, educationalist
• Harold Nelson, athlete
• William Sutch, economist, public servant
• Matthew Toynbee, cricketer