Various British broadcasters were understood to have been interested in the show, which debuts early next year on US broadcaster Fox, meaning Channel 5 has won out in a bidding war.
The show will reunite Gillian Anderson and David Duchovny as alien-hunting FBI agents Dana Scully and Fox Mulder.
“Securing the UK premiere of the hugely anticipated return of The X-Files is a major coup for the channel and will create one of the television events of 2016,” said Ben Frow, director of programmes at Viacom-owned Channel 5.
“This acquisition underlines our ambition to deliver a diverse slate of brilliant, must-see programming on Channel 5.”
The deal also hands Channel 5 The X- Files Essential Collection, which are 20 episode selected by show creator Chris Carter that tell the story of the original series.
Channel 5’s head of acquisitions, Katie Keenan, closed the deal with vendor 20th Century Fox Television Distribution.
The original ran for nine seasons, ending in 2002, with a film following in 2008.
Channel 5 becomes the latest international buyer of the new show, coming just over a week after CTV secured the rights in Canada.