The Mock The Week comedian will oversee this year's ceremony at London's Royal Festival Hall on May 27.
He is replacing last year's host Graham Norton, who will be in Azerbaijan covering the Eurovision Song Contest that weekend.
O'Briain said: "I'm delighted and honoured to be taking the reins at this year's British Academy Television Awards, in the prestigious role as the person who introduces the people who read out the winners of the awards."
Referring to the controversy over ITV's decision to cut off Adele's speech at last month's Brit Awards, he joked: "And if Adele wins anything, I promise I'll leave her well alone, no matter what time it is."
BAFTA chief executive Amanda Berry OBE added: "Dara is a fantastic supporter of BAFTA, and I know he will do a terrific job of hosting the Television Awards.
"The ceremony showcases the very best television programmes and performances of the last year, and with Dara at the helm I am sure it will be a truly wonderful event."
O'Briain also served as host for the GAME British Academy Video Games Awards on March 16.
The 2012 British Academy Television Awards will air on BBC One.