| Official Name: | Ösmo |
| Pushpin Map: | Sweden Stockholm#Sweden#European Union |
| Subdivision Type: | Country |
| Subdivision Name: | Sweden |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Nynäshamn Municipality |
| Subdivision Type2: | County |
| Subdivision Name2: | Stockholm County |
| Subdivision Type1: | Province |
| Subdivision Name1: | Södermanland |
| Area Footnotes: | [1] |
| Area Total Km2: | 2.19 |
| Population As Of: | 31 December 2010 |
| Population Total: | 3,911 |
| Population Density Km2: | 1783 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 58.9833°N 71°W |
Ösmo (in Swedish pronounced as /ˈœ̂sːmʊ/)[2] is a locality situated in Nynäshamn Municipality, Stockholm County, Sweden with 3,911 inhabitants in 2010. It has a station on the Stockholm commuter rail network, Nynäshamn line (Nynäsbanan).
There is a very old church here. The centre is modern and uninteresting, with a school, supermarket, petrol station, a couple of pizza restaurants, a handelsbanken bank and a discount store. The surrounding nature includes forest and a lake, called Muskan. A full-sized golf course and hotel lies just a few KM from the town centre.