The three-day trip, which will kick off on Wednesday 30 August, will see the Tory premier received by the Emperor of Japan Shōwa Hirohito and her Japanese counterpart Shinzo Abe, who May met with at the G20 summit in Hamburg, Germany, in July and at her official residence of Chequers in April.
"Her visit is expected to cover a wide range of bilateral and regional issues, including working together to support the rules-based international system and the promotion of free trade and democratic values," Downing Street said.
"The key visit themes are expected to be defence and security cooperation, and trade and investment opportunities.
"She will be accompanied by a delegation of business leaders drawn from a range of sectors. The delegation will showcase the strength of British business, the shared confidence in the UK-Japan economic relationship as we leave the EU, and the potential for future growth."
May's visit will come amid growing tensions in the region over North Korea's missile and nuclear weapons programme.
The rhetoric between US President Donald Trump and Kim Jong-un has slightly cooled after the North Korean despot reportedly delayed his decision to launch missiles towards Guam, an American island territory in the Western Pacific.
The hermit nation conducted two intercontinental ballistic missile tests in July, with the second missile landing in the Sea of Japan. All UN Security Council members, including China, agreed to tougher sanctions on North Korea on 5 August.
"The UK and our international partners are united in opposing and standing firm against the threat posed by North Korea. This resolution will cut the resources that North Korea is abusing to fund its reckless and illegal pursuit of nuclear and ballistic missile programmes," said Foreign Office minister Lord Ahmad of Wimbledon.
"North Korea has chosen this extremely dangerous and destabilising path. The regime is prioritising the pursuit of these weapons over and above its people, peace and stability in the region. The North Korean regime needs to change its course immediately and the UK calls on all countries to implement these new measures fully and robustly."