"I got a lovely text from her this morning congratulating me saying, 'You're going to the big top, girl!' Which was very sweet of her," Janney said, as reported by EW.
The 58-year-old actress, who is a first-time Oscar nominee, also shared that she had a group of family and friends who flew to her from New York just to be with her for the announcements.
"First of all, I was in bed last night at 9 p.m. to try to get a good night's sleep, which is just a joke — I didn't sleep one wink," Janney quipped.
"At 5 a.m. my bedroom door flew open and six people came jumping into my bed," she continued. "I was floored, I had all these people who flew in from New York to be with me. It was just the most special morning to get up and watch the announcement with dear friends and family."
"It's an extraordinary thing. It's something you dream about as an actor and for it to happen is amazing," Janney added.
In addition to speaking about her nomination, Janney also talked about I, Tonya, in which she plays Harding's mother LaVona. Harding is played by Margot Robbie.
When asked if she thinks the film "redeems Harding...who was ostracized by the public for her involvement in the attack on Nancy Kerrigan," Janney said, "I think so. If not redeem, at least it gives you more empathy for what she went through in her life."
"From her family to the skating community who didn't want to embrace her even though her talent is undeniable. They didn't think she fit so they didn't encourage her. I feel a lot of empathy for her, I think she's paid a huge price for any involvement she had in the incident with her career being taken away from her. I don't think we'll ever know what the real story is," Janney continued.
Janney is also said to have spoken highly of her co-star and fellow Oscar nominee, Robbie, as well as her competition in the Best Supporting Actress category, Octavia Spencer.
However, it was her scene-stealing co-star, the parrot that sits on her shoulder in the film, that she raved over.
"He definitely deserves [a nomination], I don't know if anyone does that for animals," Janney gushed. "He tried to steal that scene from me. Hands down my favorite animal costar and I've worked with lots of them, a lot of them on the West Wing like turkeys. This one was a special relationship we had and he fueled my performance in ways I can't imagine."