TNS can stand for:
- Taylor Nelson Sofres, a market research company
- Tao Nan School, a primary school in Singapore
- Taran Noah Smith, an American actor
- Temporal noise shaping, an audio encoding technique
- The Natural Step, a sustainability framework
- The Naturist Society, a national naturist organization based in Oshkosh, Wisconsin, USA
- The New Saints F.C., a Welsh football (soccer) club formerly sponsored by Total Network Solutions that bore the company's name from 1997 to 2006
- TNS (gene), a protein tyrosine phosphatase
- TNSrecords, a Manchester, U.K. based Punk Rock/Ska Record Label
- Transparent Network Substrate, used by Oracle database software for network communications.
- Triple Nine Society, a high IQ organisation, similar to Mensa
- Tungsten (Cantung) Airport, Tungsten, Northwest Territories, Canada