The 'Blue Jasmine' actress, joked she and husband Andrew Upton had had a "threesome" following the Academy Awards on Sunday because she couldn't bear to let the statuette out of her sight.
She said: "It's the closest my husband and I have ever come to a threesome."
The 44 year old beauty - who has sons Dashiell, 12, Roman, 9, and Ignatius, 5, with Andrew - admitted accepting the award was a bizarre experience.
She explained: "I was so stressed. I don't think I drank that much last night but it was such a release of adrenaline."
Cate appeared on Ellen DeGeneres' talk show just hours after the ceremony and admitted to the host that she had only had "a little bit of sleep".
Ellen said: "What can I get you? I have Visine, I have Advil. I have water. I have a banana."
The actress replied: "Do you have a blanket or a coffee or something?"
Ellen had arranged to have pizza delivered to the A-list audience at the Oscars, but Cate had to stop for food on her way home because she was away from her seat when the pies were distributed inside the Dolby Theater in Hollywood.
She said: "I went to the bar to try and get something to eat and then they wouldn't let me back in! But all those actresses were hovering it up so I wouldn't have got a piece anyway."
Tagged in Cate Blanchett Ellen DeGeneres andrew upton