Onslow College is a state co-educational secondary school located in Johnsonville, a suburb of Wellington, New Zealand.

Onslow College opened in 1956 to serve Wellington's rapidly growing northern suburbs.

[4] Former principal Stuart Martin described the "Onslow Way" as "socially liberal but educationally conservative, decile 10 but physically run down".

[12][13] In 2017 Onslow College won the Wellington regional "Festival Cup"[14] for the school best representing the spirit of the Big Sing,[15] a school choral festival organised by the New Zealand Choral Federation.

[19] The second building listed was the Gym (Block Q) which has an NBS ratting of 15% with the celling braces posing the greatest risk.