The singer died unexpectedly on Monday.
Diana Ross is paying tribute to Mary Wilson. In an exclusive statement to ET, Ross remembers her late friend, with whom she performed as The Supremes, along with Florence Ballard, in the '60s. Wilson died on Monday at age 76. Ballard died back in 1976.
After news broke of her death, a rep told ET that Wilson was "working on new music and was set to release a new album this spring."
"I remember Mary's joy and love during happier times and our love and years together," Ross tells ET. "I recall 'the good old days' with a smile in my heart and a song in my heart during these changing times. I'm happy to have known her. Love and condolences to her family."
Ross, Wilson and Ballard's Motown group created over a dozen No. 1 singles during its time, including hits like "Where Did Our Love Go," "Baby Love," "Come See About Me," "Stop! In the Name of Love" and "Back in My Arms Again."
Ross also released a statement on Twitter, writing, "I just woke up to this news, my condolences to you Mary's family, I am reminded that each day is a gift, I have so many wonderful memories of our time together 'The Supremes' will live on in our hearts."
In a statement to ET, Gladys Knight calls Wilson "a good friend," noting that she'll miss "her smile, her voice and her heart."
"She was my girl," Knight says. "She was soft-hearted and loving and always trying to make it work regardless of anything that was happening personally. Mary was amazing and when their voices came together she helped them blend, I loved all of them. She was always kind and knew her own strength vocally and personally, she brought something wonderful to the Supremes."
"She sung her part and didn’t need to be upfront, the warmth in her voice and music came from her soul," she continues. "Back then there weren’t a lot of places for African Americans to be and Mary made it work for her group and that was good for all of us."
Patti LaBelle also remembered the late singer, tweeting that she's "deeply saddened by the passing of the beautiful Mary Wilson!"
"She was a legend and an icon and what she contributed to the world cannot be overstated," LaBelle wrote. "I send my deepest condolences and prayers to her family, loved ones and fans."
"What an honor to have known and loved you, Mary Wilson!" Marie Osmond tweeted. "The heavens are singing for you now and your glorious return home. God bless you sweet friend."
Keep scrolling for more social media tributes to Wilson.