|Motto||Adveniat Regnum Tuum|
|Local authority||Western Education and Library Board|
Thornhill College (Irish: Coláiste Cnoch na nDealg) is a Roman Catholic grammar school for girls. It is located in Derry, Northern Ireland. It has a student population of approximately 1500 and a staff of 100 teachers.
Thornhill was founded by the Sisters of Mercy in 1886 and moved to Culmore in 1932. It moved into its new building in 2003.
Miss Marguerite Hamilton replaced Mrs. Sarah Kelly in 2010 as the school principal.
The school motto is the Latin phrase "Adveniat Regnum Tuum", which translates as "Thy Kingdom come".
Catherine McAuley, the founder of the Sisters of Mercy said: "Let us rejoice when good is done, no matter by whom it is accomplished". The school strives in the words McAuley "to fit young women for Earth without unfitting them for Heaven".
In 2009 Thornhill College became a Specialist School in Mathematics and Physics. The Specialist Schools Programme helps schools, in partnership with private sector sponsors and supported by additional Government funding, to establish distinctive identities through their chosen specialisms and achieve their targets to raise standards.
In 2015 Thornhill College was ranked in the Top Ten Grammar Schools in Northern Ireland in terms of its A-level performance. A total of 88.9% of its students entered for A-Levels achieved a grade of A* - C.
Thornhill College has a Senior Debating Society, established in 1954. The team reached final of the Northern Ireland Schools Debating Competition in 2004 and 2007, and is known throughout the school for wearing the gold stripe around the lapel of the debating blazer. Thornhill has had two teams in the semi-finals of this competition who debated against each other on 30 March 2007 in Belfast. The society meets regularly to debate topical subjects and research up and coming competitions. The school also has an established Junior Debating Society who meet after school as part of the homework club.
The school has recently erected a statue on the "teardrop" at the front of the school. The piece was constructed by Maurice Harron and the final sculpture was officially unveiled early Autumn 2008.
Notable former pupils
- Dana Rosemary Scallon - singer and former MEP
- Nadine Coyle - member of girlband Girls Aloud
- Roma Downey - actress
- Nell McCafferty - journalist, writer and playwright
- Colette Bryce - poet
- Terri Scott - educator
- Margery Jackman Catherine's Response, All Hallows School, 1996, Retrieved 2012-07-31
- Education Minister announces nine new specialist schools Northern Ireland Executive, 4 June 2008, Retrieved 2012-07-31
- "Grammar school exam performance 14/15" (PDF).