Branagh stars as Swedish detective Kurt Wallander in the BBC series
Kenneth Branagh has won the prize for best actor at the Broadcasting Press Guild Awards (BPG) for his performance in the BBC drama Wallander.
The star beat David Tennant and Ben Whishaw for his role as the Swedish detective in the three-part series.
Andrea Riseborough won the best actress award for her roles in Channel 4's The Devil's Whore and the BBC's Margaret Thatcher: The Long Walk to Finchley.
The awards will be presented later at a ceremony at London's Theatre Royal.
It is Branagh's first major TV acting award in the UK.
He follows in the footsteps of Sir Alec Guinness, Michael Gambon, Colin Firth, David Suchet and Christopher Eccleston as previous winners of the BPG best actor award.
BBC programmes dominated the awards, voted for by journalists who write about TV and radio, winning 13 of the 15 prizes.
BBC Four's Margaret Thatcher drama also won two other awards for best single drama and the multi-channel award, for the best programme shown on a digital channel.
BBC sitcom Outnumbered was named best comedy/entertainment
The Devil's Whore was named best drama series.
The Apprentice picked up the award for best factual entertainment, while BBC One sitcom Outnumbered won best comedy/entertainment and the writer's award.
The BBC's business editor Robert Peston won best TV performer in a non-acting role and Radio 4's Today Programme host Evan Davis was named radio broadcaster of the year.
The Radcliffe & Maconie Show on Radio 2 took the honour of radio programme of the year.
Sir David Frost will receive the Harvey Lee award for outstanding achievement, for his career on and off the screen.
The Broadcasting Press Guild was founded in 1974 and is made up of journalists who specialise in television, radio and the media.