Asquith Girls High School, (abbreviated as AGHS) is a government-funded comprehensive single-sex secondary day school for girls, located on Stokes Avenue, Asquith, an upper north shore suburb of Sydney, New South Wales, Australia.

Established in 1959 to replace the Hornsby Home Science School, the school enrolled approximately 597 students in 2018, from Year 7 to Year 12, of whom two percent identified as Indigenous Australians and 30 percent were from a language background other than English. The school is operated by the NSW Department of Education in accordance with a curriculum developed by the New South Wales Education Standards Authority; the principal is Elizabeth Amvrazis.

The school's brother school is the Asquith Boys High School.

In February 1958, the NSW Department of Education acquired a two-hectare (five-acre) site in eastern Asquith for a new girls high school to replace the Hornsby Home Science School (established 1947) that was destroyed with other school buildings on Peats Ferry Road in a bushfire in 1957. Asquith Girls High School officially commenced operation from 1 January 1959.

The following individuals have served as principal of Asquith Girls High School:

Ordinal	Officeholder	Term start	Term end	Time in office	Notes
−	Alma Hamilton
−	Kristine Needham		2006
−	Jane Ferris	2006	2013	6–7 years
−	Elizabeth Amvrazis	2013	incumbent	10–11 years

• Micky Green – pop singer

• List of government schools in New South Wales: A–F
• Education in Australia

• Asquith Girls' High School; Duke, Barbara; King, Diane (1966), Asquith Girls' High School, G.W. Hall & Co.
• Dewey, Patricia (2005), A history of Hornsby Home Science Secondary School Pacific Highway Hornsby, P. Dewey

• Official website
• NSW Department of Education School Finder – Asquith Girls High School
• Asquith Girls High School P&C website