TNA may refer to:
Organisations
- Tamil National Alliance, a political coalition in Sri Lanka
- The National Alliance, a political party in Kenya
- The National Archives (United Kingdom), a UK public body
- Tonga Nurses' Association, a trade union
- Trans Nation Airways, an Ethiopian charter airline
Science and technology
- Threose nucleic acid, an artificial genetic polymer
- 2,4,6-Trinitroaniline, a nitrated amine
- Time and attendance, a system that monitors and records employee attendance
Sports
- Total Nonstop Action Wrestling, the former name of an American professional wrestling promotion, now known as Impact Wrestling
- Torneo Nacional de Ascenso, a division of the Argentine basketball league
Transport
- TNA, IATA code for Jinan Yaoqiang International Airport, China
- TNA, ICAO code for TransAsia Airways
- TNA, National Rail code for Thornton Abbey railway station
Other uses
- TNA (Airborne nuclear warhead), a French thermonuclear warhead
- TNA, a clothing brand of Aritzia
- tna, ISO 639 code for Tacana language
- TNA Media, owner of The New Age
- TNA Park, a multi-use stadium in Tarkwa, Ghana
- Tashi Namgyal Academy, a public school in Sikkim, India
- The New American, a print magazine
- Training needs analysis, the process of identifying the gap between training and needs