Satellite operator Kacific Broadband Satellites said it had signed a 15-year agreement with the state-owned Tonga Satellite.
It would connect communities in nearly 90 remote outer islands with high speed internet, Kacific said.
Kacific chief executive Christian Patouraux said until now, rural areas depended on urban centres to distribute bandwidth to them.
"With Kacific's solution for Tonga, urban centres need rural and remote areas in reciprocal cooperation to complete the urban infrastructure build up," he said.
Satellite bandwidth supplied by Kacific will prioritise hospitals, health clinics, schools, police stations and other government infrastructure.
It could be redistributed to the country's main centres in the event of a cable outage.
In January, Tonga went offline for two weeks after an undersea, fibre-optic cable failed.
Police said in February they were investigating whether the cable cutting was intentional.