As of November 2024, Hagley College has roll of 1,941 students, of which 171 (8.8%) identify as Māori.

[4] Unlike most New Zealand high schools there is no uniform requirement and students may address their teachers on a first name basis.

Over 92% of students leave with qualifications and a substantially greater proportion than the national average go on to graduate from a New Zealand university.

[11] Principal Brent Ingram lobbied the Ministry of Education in the 1990s to have the main building earthquake-strengthened.

The building came through the February 2011 Christchurch earthquake reasonably unharmed and, according to Ingram, "didn't lose a brick".