Timaru Girls' High provides education for girls aged between 13–18 years of age (class levels – years 9 to 13).

It also has a boarding facility within the school grounds for pupils not living in Timaru itself and also caters for international students.

The school motto is Scientia Potestas Est – Knowledge is Power.

The school is a stone's throw away from the Catholic Roncalli College.

The school has 4 colour houses named after New Zealand native flowers and each student is put into one of them to encourage team spirit.The colours are: There are several House events per year, Swimming Sports, Athletics, Cross Country, Aitkens and Waters Cup Day and House Choirs In September 2011, a school girl wanted to support the country's Blue Friday, a nationwide campaign to raise awareness of prostate cancer.