Julianne Hough: 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!

Gabrielle Union: Grease is my #1 movie of all time and made me a lifelong Olivia Newton John fan. Me and my sister watched Xanadu more times than I could count. Sending so much love and prayers to a real gift of a woman and talent.

Kathy Griffin: Olivia Newton-John rolled with EVERYTHING.

Fran Drescher: Dear sweet wonderfully talented @therealonjOlivia 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.

George Takei: 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.