The newsroom drama - which starred Dominic West and Ben Whishaw - will not return for a third series, Broadcast reports.
A BBC spokesperson said: "We loved the show but have to make hard choices to bring new shows through."
Jane Featherstone, chief executive of producers Kudos Film and Television, said that she was "sad and disappointed" by the BBC's decision.
The first series of The Hour launched with 2.89 million viewers in July 2011, but the show's second run fared less well in the ratings, opening with just 1.68 million.
The period thriller's creator Abi Morgan previously admitted that she would "love" to write a third series.
"I love those characters and I'm really excited to create more characters, so fundamentally I'd love to see it develop and grow," she said in November.
Romola Garai - who played Bel Rowley - also told Digital Spy that she would be interested in starring in more The Hour episodes.
"I don't think the format of this show lends itself to running for 10 or 15 years, but hopefully we'll do some more," said the actress.
> Ben Whishaw: 'The Hour is darker, more shocking than ever before'
Watch a trailer for the last series of The Hour below: