In an interview set to air Wednesday, Harrelson, 48, tells Ellen DeGeneres that his mom was thrilled that he received a Best Supporting Actor nomination this year.
"I got a note from my mom, and she said, 'You finally arrived. You've been nominated in the same category with Christopher Plummer,' " Harrelson says on The Ellen DeGeneres Show. "So, I got my mom's approval, which is enough, you know what I mean? I don't need a statue."
Not that he expects one. "I look at being nominated as a win," he says. "I have to think that way. I think my chances of winning are probably about less than 1 percent."
"So, if you win, you'll be flipping out," DeGeneres says. "Oh, yeah," he replies.
Plummer, 80, is also enjoying his first Oscar nomination, for his work in The Last Station. He and Harrelson are joined in the category by Matt Damon for Invictus, Stanley Tucci for The Lovely Bones and Christoph Waltz for Inglourious Basterds.
Plummer recently said that he expects Waltz to win. Harrelson just figures it'll be anyone but himself.
"They're all better than me, and I'll admit it," he says. "No, I feel lucky just to be nominated with all these guys."
The 82nd Annual Academy Awards will be presented on Sunday, March 7, and televised live on ABC beginning at 5 p.m. PT/ 8 p.m. ET.