Södertörn is a peninsula in Sweden, making up the eastern part of the Södermanland province, protruding into the Baltic Sea. On northern Södertörn are the southern suburbs of Stockholm.
This article covers mainland Södertörn except Stockholm municipality, namely Botkyrka, Haninge, Huddinge, Nacka, Nynäshamn, Salem, Södertälje and Tyresö. Islands in the area are covered in Stockholm archipelago.
All built-up areas in Södertörn are served by public transport (SL).
Much of the area is served by local trains.
- Litografiska museet, , a museum on litographic printing.
- Tumba Papermill Museum , The paper mill in Tumba has a 250-year history of making Swedish banknotes. The exhibitions tell the story of the Bank of Sweden, the world's first central bank, as well as the first one to issue paper money.
- Flottsbrobacken in Huddinge, alpine skiing.
- Nackareservatet. Notably Hellasgården  (local bus from T Slussen), an activity centre and a cafe. Lake swimming (there'a a sauna for those of you longing for that winter swim), running, skiiing, ice-skating, mountanbiking and much more. Or just take a walk in the forest.
- Tyresta National Park  20 kilometers from central Stockholm. A part of the park was devastated by a wildfire in 1999. The park management lets it recover naturally.
- Bornsjön— For a real wild animal safari close to Stockholm, Bornsjön is the best spot. It is a nature reserve 30 minutes drive south of Stockholm. The natural environment is perfect here for watching mammals like moose, roe deer and wild boar. Stockholm Outback offers tours down to the reserve every evening during the summer. For further information call +46 73-6578708 or visit their homepage .
Except Stockholm, nightlife in Södertörn is concentrated to Södertälje and Nynäshamn.
- Nynäs havsbad , a four-star waterfront hotel in Nynäshamn.
- Quality Hotel Park, a hotel in central Södertälje.
- Grand Hotel Saltsjöbaden , is a Grand Old Hotel famous for the 1938 Saltsjöbaden Agreement between the Swedish Labor Confederation (LO) and the Employer Union (SAF), still maintaining stability on the Swedish labor market.
- Södertörn University in Flemingsberg. 
There are ferries to Gotland, Gdynia (Poland) and Ventspils (Latvia). from Nynäshamn. (J Nynäshamn)