Gmina Mikołajki is an urban-rural gmina (administrative district) in Mrągowo County, Warmian-Masurian Voivodeship, in northern Poland. Its seat is the town of Mikołajki, which lies approximately 21 kilometres (13 mi) east of Mrągowo and 72 km (45 mi) east of the regional capital Olsztyn. The gmina covers an area of 256.41 square kilometres (99.0 sq mi), and as of 2006 its total population is 8,435 (out of which the population of Mikołajki amounts to 3,848, and the population of the rural part of the gmina is 4,587). The gmina contains part of the protected area called Masurian Landscape Park.