Gmina Tarnowiec is a rural gmina (administrative district) in Jasło County, Subcarpathian Voivodeship, in south-eastern Poland. Its seat is the village of Tarnowiec, which lies approximately 9 kilometres (6 mi) east of Jasło and 44 km (27 mi) south-west of the regional capital Rzeszów.
The gmina covers an area of 63.1 square kilometres (24.4 sq mi), and as of 2006 its total population is 9,130.
Gmina Tarnowiec contains the villages and settlements of Brzezówka, Czeluśnica, Dobrucowa, Gąsówka, Gliniczek, Glinik Polski, Łajsce, Łubienko, Łubno Opace, Łubno Szlacheckie, Nowy Glinik, Potakówka, Roztoki, Sądkowa, Tarnowiec, Umieszcz and Wrocanka.
Gmina Tarnowiec is bordered by the town of Jasło and by the gminas of Chorkówka, Dębowiec, Jasło, Jedlicze and Nowy Żmigród.