The square is located in the central district of St. Petersburg and is the place where Malaya Sadovaya Street, Nevsky Prospect, Zodchego Rossi Street and Krylov Lane converge.

The square contains historical and cultural monuments of federal significance: the Alexandrinsky Theatre, the Russian National Library, the Anichkov Palace, the monument to Catherine II, the buildings of the Ministry of Public Education and the Directorate of Imperial Theatres on Zodchego Rossi Street, the building of the St. Petersburg City Credit Society.

Ostrovsky Square is the work of the brilliant mind of the outstanding architect Carlo Rossi. And despite the fact that K. I. Rossi failed to implement the entire plan, the ensemble of Ostrovsky Square remains one of the highest achievements of Russian urban planning art. As part of the historical development of the center of St. Petersburg, the square is included in the World Heritage List.