Gmina Pacyna is a rural gmina (administrative district) in Gostynin County, Masovian Voivodeship, in east-central Poland. Its seat is the village of Pacyna, which lies approximately 22 kilometres (14 mi) south-east of Gostynin and 89 km (55 mi) west of Warsaw.
The gmina covers an area of 90.85 square kilometres (35.1 sq mi) and in 2006 its total population was 3,947.
Gmina Pacyna contains the villages and settlements of Anatolin, Janówek, Łuszczanówek, Luszyn, Model, Pacyna, Podatkówek, Podczachy, Przylaski, Radycza, Raków, Rakowiec, Remki, Robertów, Romanów, Rybie, Sejkowice, Skrzeszewy, Słomków and Wola Pacyńska.
Gmina Pacyna is bordered by the gminas of Gąbin, Kiernozia, Oporów, Sanniki, Szczawin Kościelny and Żychlin.