The Zegrze Fortress () is a military structure located in Zegrze, Poland, on a high escarpment over the Narew River. Built in late 19th century by the Russian Empire, it was to guard a river crossing across the Narew. Modernised between 1902 and 1907, it was part of the so-called Warsaw Fortified Area () comprising three major nodes: the Warsaw Fortress, Modlin Fortress and Zegrze.