The Ministry of Fisheries is selling fresh in Nuku'alofa for as low as two and a half pa'anga, or $US1.12 per kilogramme.
CEO Tu'ikolongahau Halafihi said the initiative aimed to ensure affordable and healthy food was available.
Dr Halafihi said the six tonnes of fish were part of a 45 tonne catch from a Taiwanese operator and came under an agreement to provide part of their catch to be sold locally.