Gmina Nielisz is a rural gmina (administrative district) in Zamość County, Lublin Voivodeship, in eastern Poland. Its seat is the village of Nielisz, which lies approximately 18 kilometres (11 mi) north-west of Zamość and 60 km (37 mi) south-east of the regional capital Lublin.

The gmina covers an area of 113.16 square kilometres (43.7 sq mi), and as of 2006 its total population is 6,025 (5,723 in 2013).

Gmina Nielisz contains the villages and settlements of Deszkowice-Kolonia, Gościniec, Grobla, Gruszka Duża, Gruszka Duża-Kolonia, Gruszka Mała Druga, Gruszka Mała Pierwsza, Kolonia Emska, Krzak, Las, Nawóz, Nielisz, Niwa, Poprzeczka, Ruskie Piaski, Średnie Duże, Średnie Małe, Staw Noakowski, Staw Noakowski-Kolonia, Staw Ujazdowski, Staw Ujazdowski-Kolonia, Ujazdów, Wólka Nieliska, Wólka Złojecka, Zamszany, Zarudzie and Złojec.

Gmina Nielisz is bordered by the gminas of Izbica, Rudnik, Stary Zamość, Sułów, Szczebrzeszyn and Zamość.

• Polish official population figures 2006