The Hollywood icon was triumphant in 1954 for the movie, and is now 93-years-old.
She joked as she took to the stage to present the Academy Award for Costume Design that she was “older than the Academy”.
In an emotional moment, she paid tribute to her late husband Jeffrey Hayden, who died on Christmas Eve in 2016 at the age of 90.
Viewers at home were stunned by her appearance.
“This is the Oscars I grew up on and loved–a great old person coming out and talking for a while and making me want to learn about their movies. Respect to Eva Marie Saint,” wrote Mark Harris on Twitter.
“Eva Marie Saint looks fabulous. Good for her,” said Roxane Gay.
Richard Marx tweeted: “Every single one of us needs to start doing whatever #evamariesaint has been doing. 93 years young. Amazing.”
Other comments included: “Eva Marie Saint is more on-it at 93 than I am right now, or have ever been.”
“Eva Marie Saint was always such an elegant and poised woman, but it is insane that she’s 93 years old. She looks amazing,” read an additional post.
The award she was presenting went to Phantom Thread.
Read rolling coverage of the Oscars here.