The "No Tears Left to Cry" star took to Instagram to pen a sweet message for the "Poker Face" hitmaker on Saturday (March 28), sharing a snap of the two alongside a short note.
"happy birthday to a literal angel that has changed my life in many ways ! i'll tell u more about it later but ... u make my heart feel so full and happy and understood @ladygaga," Ariana captioned her post. "Wishing u all the joy in the world today and every day ! have some pasta."
The "Bad Romance" star also received a birthday message from her friend and collaborator Tony Bennett, 93, with whom she released the joint album "Cheek to Cheek" in 2014.
"Lady, happy birthday. Have a beautiful day," Bennett said in his sweet clip.
The celebrations come after GaGa announced earlier this week (begins March 23) she was delaying the release of her forthcoming album "Chromatica", featuring the single "Stupid Love", as it "just doesn't feel right to me to release this album with all that is going on" amid the coronavirus pandemic.