The Jurassic Park actress shared an image of the mother-daughter duo wearing red swimsuits in tribute to Ladd's 87th birthday Tuesday.
"Happy birthday, goddess mama!" Dern, 55, wrote. "You are my endless inspiration and my favorite buddy to go for a swim with!! And just the best darn actor EVER!"
"Possibly greatest acting ever…Diane Ladd in Rambling Rose…scene with her, Robert Duvall and Kevin Conway…spine tingling perfection….." one follower wrote.
"Your Mom's rendition of Marietta Fortune is by far some of the best acting of all time," another fan commented. "She played that role so damned good.'"
Dern gave a similar tribute last year, sharing how much love she has for her mum.
"Nothing like waking up my cutie mama on her birthday surrounded by friends and cakes!" she wrote of the Mississippi-born film veteran, who has acted in over 100 projects. "I love you beyond measure, amazing Diane!!!!!!! I'm such a blessed daughter."
The mom of two took to Instagram to celebrate Jaya on her 18th birthday sharing a photo carousel featuring pictures of Jaya as a little girl, as well as a more recent picture.
"My girl is 18 today!!!" the proud mom wrote. "Happiest birthday, Jaya! You teach me every day about what it means to be an honest and profound empath, artist, and activist."
"I love you with everything," Dern concluded.
In March, the Jurassic World Dominion star, 55, appeared on an episode of The Ellen DeGeneres Show where she opened up about her teen's ambition to be an actress. Dern told host Ellen DeGeneres that she's excited for Jaya to eventually be the family's third generation of actors following herself and her parents Ladd and Bruce Dern.
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"There is something very moving about it," she explained. "Jaya's 17 and I started very young at 11 but I'm so happy that she's waiting and wants to go to school but really knows in her heart she wants to act."
"And maybe if she does, we'll end up having the privilege of working together," Dern added.