Grönvik, previously Sumpviken, is a village and part of the village of Iskmo in the municipality of Korsholm, western Finland. The village lies on a stretch of coast, approximately 3 km long, stretching a few hundred metres up country, and around 500 metres along the Jungsundvägen road, with about a hundred metres of area around the road being inhabited. Road 724, Alskatvägen, passes through the village. The third named road found in Grönvik is Långkärrvägen.