| Official Name: | Mosterhamn |
| Other Name: | Moster |
| Settlement Type: | Village |
| Pushpin Map: | Vestland#Norway |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location of the village |
| Subdivision Type: | Country |
| Subdivision Name: | Norway |
| Subdivision Name1: | Western Norway |
| Subdivision Name2: | Vestland |
| Subdivision Type3: | District |
| Subdivision Name3: | Sunnhordland |
| Subdivision Type4: | Municipality |
| Subdivision Name4: | Bømlo |
| Utc Offset1: | +01:00 |
| Utc Offset1 Dst: | +02:00 |
| Area Total Km2: | 1.8 |
| Population As Of: | 2019 |
| Population Total: | 1375 |
| Population Density Km2: | 764 |
| Postal Code Type: | Post Code |
| Postal Code: | 5440 Mosterhamn |
| Elevation M: | 2 |
| Elevation Footnotes: | [1] |
| Coordinates: | 59.6992°N 5.3856°W |
Mosterhamn or simply Moster is a village in Bømlo municipality in Vestland county, Norway. The village is located on the small island of Moster in the southeastern part of the municipality of Bømlo. The village lies along the Bømlafjorden. The 1.8km2 village has a population (2019) of 1,375 and a population density of .[2]
The village is notable since the Old Moster Church is here and that is the site of the Mostratinget, a thing in the year 998 when Olav Tryggvason is said to have brought Christianity to Norway and made it the national Church of Norway.[3]
Prior to the opening of the Triangle Link bridge-tunnel network in 2001, Mosterhamn was one port of the Mosterhamn–Valevåg Ferry which crossed the Bømlafjorden.