Gustav Adolf Grammar School
| Gustav Adolf Grammar School Gustav Adolfi Gümnaasium | |
|---|---|
| The main building of the Gustav Adolf Grammar School decorated in 2021 for anniversary with small portraits of all students | |
| Address | |
| Suur-Kloostri 16 , , 10133 Estonia | |
| Information | |
| Type | Public | 
| Motto | Vanim, vaimne, väärikas (Oldest, spiritual, dignified) | 
| Established | 16 February 1631 | 
| Founder | Gustav II Adolf | 
| Principal | Henrik Salum | 
| Grades | 1–12 | 
| Number of pupils | 1,530 | 
| Color(s) | Green, purple, blue, white | 
| Nickname | GAG | 
| National ranking | 3rd | 
| Website | www.gag.ee | 
The Gustav Adolf Grammar School is a secondary school in Tallinn, Estonia. Swedish king Gustavus Adolphus established it as the Reval Gymnasium in 1631. It is one of the oldest extant secondary schools in Europe.