Japan's Nuclear Regulation Authority (NRA) has given a formal safety approval for restarting Kyushu Electric Power's two-reactor Sendai plant in south-western part of the country.
The final approval for the restart came after a public consultation period.
The preliminary approval had already been secured by the Sendai plant in July this year.
The Sendai plant still needs to get local approval to restart and must pass on-site operational inspections, according to Kyodo news agency.
This could mean that the plant is not likely to commence operations before December.
All 48 reactors in Japan had been halted following the devastating nuclear disaster at the Fukushima plant, which had led to vehement public opposition and mistrust of the sector.
Before the disaster at the Fakushima plant, nuclear plants catered to around 30% of Japan's power requirements.
In September 2013, the country's last reactor at Ohi in western part was pulled offline.
As Japan's 48 nuclear reactors are not operational, the country depends on additional imports of coal and gas for power generation.
These facilities have been closed either for scheduled maintenance or because of safety concerns.
Prime Minister Shinzo Abe has been pushing for the reopening of several of these nuclear plants, as long as they meet the safety criteria.
The government is also urging regulatory authorities to decide whether to decommission the oldest of the country's 48 reactors.
The government believes that taking reactors that are more than four decades old offline may help win public trust on nuclear plants.
Following the Fukushima disaster, the country's law mandates that reactors have to be decommissioned after 40 years and they can receive a 20-year extension only after passing through stringent safety measures.