The $US79.59 million facility is being funded through mulitple grants with the Asian Development Bank contributing $US21.3 million, the Australian government providing $US14.08 million and the Green Climate Fund supplying $US26.91 million.
The Nauru government is also providing counterpart financing of $US17.3 million.
It is due to open in December 2020 and is designed to fit Nauru's needs until at least 2050.
Currently, a third of Nauru's foreign revenue is earned from fishing licences and the aim of the port is to enhance this revenue stream.
The Asian Development Bank project manager for the port, Pivi Indrawansa, said fees from about 300 foreign fishing vessels operating in Nauru waters would be the start of this.
Mr Indrawansa said vessels currently have to berth in other countries to transfer their catches.
"All these fishing vessels operating in Nauru waters will come to this port for trans-shipment to their mother ships from the fishing vessels and that income alone will generate a huge income for the country other than the fishing licences revenue," Pivi Indrawansa said.
Pivi Indrawansa said the port will also provide Nauru with the opportunity to develop fish processing facilities on the island.