Kirkkonummi is situated on the northern shore of the Gulf of Finland and borders Espoo, Vihti, Siuntio and Ingå.

The municipality is located just outside the Helsinki Metropolitan Area, bordering the city of Espoo in the east.

In recent years, Kirkkonummi has faced the highest population growth rate in the country, at over 3% per annum.

Geographically, Kirkkonummi has two famous peninsulas, namely Porkkala and Upinniemi, the latter one of which houses a major Finnish naval base.

Kirkkonummi has a four-season humid continental climate (Köppen: Dfb) with long, cold, snowy winters, and warm summers; spring and fall are somewhat cool and brief seasons.

Results of the 2011 Finnish parliamentary election in Kirkkonummi: Places of interest located in Kirkkonummi include the medieval stone church in the municipal centre, the wooden church in the village of Haapajärvi, as well as the Hvitträsk manor designed by Finnish architects Eliel Saarinen, Herman Gesellius and Armas Lindgren.