Pentwater is a village in Oceana County in the U.S. state of Michigan. The population was 958 at the 2000 census. The village is located within Pentwater Township. Pentwater is home to Mears State Park. The name Pentwater comes from Pent or Penned up waters. The entrance to the channel is notoriously shallow and for many years dictated the size of vessels that the village was able to accommodate.
According to the United States Census Bureau, the village has a total area of 1.6 square miles (4.2 km²), of which, 1.3 square miles (3.4 km²) of it is land and 0.3 square miles (0.9 km²) of it (20.25%) is water.
As of the census of 2000, there were 958 people, 463 households, and 301 families residing in the village. The population density was 733.8 per square mile (282.4/km²). There were 904 housing units at an average density of 692.5 per square mile (266.4/km²). The racial makeup of the village was 97.60% White, 0.21% African American, 0.31% Native American, 0.42% Asian, 0.10% Pacific Islander, 0.63% from other races, and 0.73% from two or more races. Hispanic or Latino of any race were 1.15% of the population.