“✨20 years today✨ #AlmostFamous,” Hudson, 41, wrote alongside a throwback pic from the movie.
Hudson played groupie Penny Lane in the popular film, which followed a teen who lands an eye-opening assignment writing about a rock band for Rolling Stone magazine. The gig requires going on tour with the group, named Stillwater.
Deschanel, who played Anita Miller, also dug out old photos, sharing film stills on Instagram.
"20 years of Almost Famous! ❤," she captioned the slideshow.
The film’s director, Cameron Crowe, also commemorated the anniversary.
"Thanks to everybody for this wonderful 20th Anniversary for Almost Famous!!” Crowe wrote. “I'll always remember this moment, just after the last shot in Central Park. With love and huge appreciation for the cast and crew and all our friends.”
Thanks to everybody for this wonderful 20th Anniversary for Almost Famous!! I'll always remember this moment, just after the last shot in Central Park. With love and huge appreciation for the cast and crew and all our friends... pic.twitter.com/w1ocuvjBB7
ET spoke with Hudson back when the film was made and she said she was so eager to work with Crowe that she would have happily played an extra. Instead, she tried out for the role Deschanel later landed.
“I read for the part of Anita, which is Cameron's sister,” Hudson, then 21, told ET. “Actually, the strange thing was I didn't know what I was reading for. Basically I got told that Cameron Crowe is doing a movie and I said I will be an extra!”
“I found Penny Lane's character to be such an amazing female role,” she also said. “I got totally sucked into her life and when I did walk onto set, my emotions were so surfaced because of all the work that we had done. It was very easy for me to go different places.”
Hudson also said she had a “strong, gut feeling” the role would become significant to her career. Sure enough, she earned a Golden Globe and an Academy Award nomination.
In 2017, Hudson shared that she had showed her son, Ryder, the movie and he "loved every second."