The Stedelijk Gymnasium Leiden is the biggest gymnasium-only school in the Netherlands, with over 1,800 pupils (in 2014).

After the Siege of Leiden (1573–1574) Nicholaus Stochius was named rector.

The name Stedelijk ('municipal') Gymnasium was introduced in 1838, together with a new educational approach.

Since 2001 Stedelijk Gymnasium organizes the Leiden Model United Nations (LEMUN), which is part of the international Model United Nations (MUN)-conferences.

The Stedelijk Gymnasium has contacts with schools from Sweden, Poland, Hungary, Germany, Italy and Belgium to exchange students.