Joining the ladies at the celebrity-friendly parlour was Cate's husband Andrew Upton and Amy's fiancé Darren Le Gallo, who was also said to be sporting a bandage.
While Cate and Amy haven't starred in any films together, they appear to be firm friends. Many have speculated that the two women bonded over the loss of their good friend Philip Seymour Hoffman, who died earlier this year from a drug overdose.
"He was beautiful," Amy said of the Capote star in an interview with Inside the Actors Studio. "I just really loved him and I know so many people did."
After Philip's death, Cate was seen bringing gifts to the apartment lived in by his partner Mimi O'Donnell and their three children.
On Monday, Cate revealed to E! News that she almost missed her Oscar win — because she was sipping cocktails with a fellow nominee.
"I was with Julia Roberts in the bar for rather too long and just got back to my seat in time," the 44-year-old Australian actress admitted.
"The blessing and curse of this (award) is it happens at the a**e end of the evening. So you watch so many other extraordinary people get up there, and you lose track of the fact that you're even nominated. Then you get taken by surprise."