Gmina Sanniki is a rural gmina (administrative district) in Gostynin County, Masovian Voivodeship, in east-central Poland. Its seat is the village of Sanniki, which lies approximately east of Gostynin and west of Warsaw.
The gmina covers an area of , and as of 2006 its total population is 6,542.
Gmina Sanniki contains the villages and settlements of Aleksandrów, Brzezia, Brzeziny, Czyà ¼ew, Dziaà Ây, Krubin, Lasek, Lubików, Lwówek, Mocarzewo, Nowy Barcik, Osmolin, Osmólsk Górny, Sanniki, Sielce, Staropol, Stary Barcik, Szkarada, Wólka Niska and Wólka Wysoka.
Gmina Sanniki is bordered by the gminas of Gàbin, Ià Âów, Kiernozia, Pacyna and Sà Âubice.