Tonga may refer to five different languages:
- Tongan language, or Tonga (ISO 639-3: <code>ton</code>) – a Polynesian language spoken in Tonga in the South Pacific
- Tonga language (Zambia and Zimbabwe), or Chitonga (ISO 639-3: <code>toi</code>) – a Bantu language spoken in Zambia and Zimbabwe
- Tonga language (Malawi), (ISO 639-3: <code>tog</code>) – a dialect of Chitumbuka (Tumbuka) language spoken in Nkhata Bay District in Malawi
- Tonga language (Mozambique), or Gitonga (ISO 639-3: <code>toh</code>) – a Bantu language spoken in Mozambique
- Ten'edn, also known as Tonga or Mos (ISO 639-3: <code>tnz</code>) – a Mon-Khmer language spoken in Thailand and Malaysia