Mikołajki is a resort town situated in north-eastern Poland within the Warmian-Masurian Voivodeship. Located in Mrągowo County, the town has a population of 3,338 inhabitants as of 2025.
The town is positioned near Śniardwy, which is the largest lake in both Poland and the Masurian Lake District. It sits in the center of the ethnocultural region of Masuria.