Moments ago, she tweeted: 'It's official! I'm hosting the #Oscars! I'd like to thank @TheAcademy, my wife Portia and, oh dear, there goes the orchestra."
"As a longtime friend, we had always hoped to find a project for us to do together and nothing could be more exciting than teaming up to do the Oscars," they said in a statement.
Ellen hosted the show in 2007 and got good reviews. USA TODAY TV critic Robert Bianco wrote: "A general aura of good feeling pervaded the evening, and much of it stemmed from the night's unfailingly sunny host, Ellen DeGeneres."
The Academy Awards will be broadcast live on March 2 on ABC.