The singers, who toured together with their respective groups in 2011 and 2012, have teamed up to form duo, Nick & Knight.
Nick & Knight announced their new formation on US talk show Good Morning America on Wednesday (30 April).
The pair will be embarking on a 39-date tour across the US kicking off on 15 September, with an album due for release on 2 September.
Nick & Knight have already launched a website and have detailed their collaboration in a video posted to YouTube.
Excited fans don't have to wait too long to hear their new music either, as they can preorder their album and get a free download of their first single, 'Just The Two of Us'.
"Me and Nick have combined our talents, our super powers, and now we are a new duo called Nick & Knight," said Jordan on GMA. "We recorded a whole new album and are going on tour.
"We're almost pretty much done with the album," he continued. "It's a bunch of pop, rock, R&B and urban. It's all mixed together to create Nick & Knight."
Backstreet Boys and New Kids On The Block have sold around 160 million albums combined all over the world. Both Nick and Jordan have also pursued solo careers.
It's been a busy few months for Nick - who married long-term girlfriend Lauren Kitt on 12 April - as he's currently on Backstreet Boys' world tour, which doesn't wrap up until July.
Elsewhere, New Kids On The Block are set to star in their own eight-episode reality show in the US, called Rock This Boat: NKOTB.
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