"My dearest Olivia, you made all of our lives so much better. Your impact was incredible. I love you so much. We will see you down the road and we will all be together again. Yours from the first moment I saw you and forever! Your Danny, your John," Travolta penned on Instagram alongside a snap of Newton-John.
Other celebrities poured their hearts out about the passing of the beloved Xanadu star, with Andy Cohen writing on Instagram alongside a video of Newton-John showcasing her amazing vocals, "Hopelessly Devoted to YOU, Olivia Newton John. Rest In Peace, Queen. Thank you for the music."
Star Trek actor George Takei paid tribute on Twitter writing, "We have lost a great, iconic artist in Olivia Newton John, gone too soon from us at age 73. I trust she is now in the great Xanadu beyond. Know that we are forever hopelessly devoted to you, Olivia. Rest in song and mirth."
Fran Drescher shared a photo of herself and the Australian born star together on Instagram alongside a note which read, "Dear sweet wonderfully talented Olivia Newton John has passed at 73. She lived a big life, always shining her light on us all with her warmth and radiance. My heart breaks for her family, for they most of all know what a profound loss this is. She was a selfless human being, far better than most, and the world just got a little darker without her light. My deepest condolences, 🥲❤️🙏🏾 fran."
Julianne Hough, who played Sandy in Grease Live!, also shared kind words about Newton-John on Instagram. "Like so many, Olivia has always been my hero. Discovering her magnetic energy as an artist and actress came first but it was her heart that truly captured mine. Forever an icon and legend!" she penned.
As OK! previously reported, the multi-talented entertainer passed away peacefully at her ranch in Southern California on Monday, August 8.
"Olivia has been a symbol of triumphs and hope for over 30 years sharing her journey with breast cancer. Her healing inspiration and pioneering experience with plant medicine continues with the Olivia Newton-John Foundation Fund, dedicated to researching plant medicine and cancer," her husband John Easterling said in part in an official statement. "In lieu of flowers, the family asks that any donations be made in her memory to the Olivia Newton-John Foundation Fund."