Gmina Konstancin-Jeziorna is an urban-rural gmina (administrative district) in Piaseczno County, Masovian Voivodeship, in east-central Poland.

Its seat is the town of Konstancin-Jeziorna, which lies approximately 8 kilometres (5 mi) east of Piaseczno and 17 km (11 mi) south-east of Warsaw.

The gmina contains part of the protected area called Chojnów Landscape Park.

Apart from the town of Konstancin-Jeziorna, Gmina Konstancin-Jeziorna contains the villages and settlements of Bielawa, Borowina, Cieciszew, Ciszyca, Czarnów, Czernidła, Gassy, Habdzin, Kawęczyn, Kawęczynek, Kępa Okrzewska, Kierszek, Łęg, Obórki, Obory, Okrzeszyn, Opacz, Parcela-Obory, Piaski, Słomczyn and Turowice.

Gmina Konstancin-Jeziorna is bordered by Warsaw, by the towns of Józefów and Otwock, and by the gminas of Góra Kalwaria, Karczew and Piaseczno.