Pop titan Beyonce welcomed a “good day”, while Winfrey said she cried tears of joy after Chauvin was found guilty on Tuesday.
Chauvin, 45, was convicted of murder and manslaughter after pinning Floyd, 46, to the ground with his knee in Minneapolis last year.
The incident was caught on camera and the harrowing video triggered a racial justice movement across the US that quickly spread to the rest of the world.
Following a high-profile trial, Chauvin was on Tuesday found guilty on all charges – second-degree unintentional murder, third-degree murder and second-degree manslaughter.
US president Joe Biden welcomed the verdict, while Beyonce and Winfrey, two of the most prominent black women in America, led the response from Hollywood.
In a statement shared on her website alongside a childhood picture of Floyd sleeping in his mother’s arms, Beyonce said: “After too many years of misguided justice, today is a good day.
“I encourage all of us to continue to pray for George Floyd’s family and for all the families who seek justice for their loved ones who are victims of too many years of inequalities.”
Winfrey said she was brought to tears when the verdict was read.
She wrote on Instagram: “Relieved—and emotional in ways I didn’t expect. I cried tears of joy as each verdict was read. I’m grateful to the witnesses and their testimonies.”
Winfrey said she was “grateful to Darnella Frazier”, the teenager who filmed Chauvin kneeling on Floyd.
She added: “Grateful to every Juror for seeing and acknowledging what the world saw on that tape. Thank you God for real! #GeorgeFloyd.”
Chart-topping singer Mariah Carey tweeted “Hallelujah!!!!!!!!” in response to the news, before adding: “A beginning.. a small grain of hope for our future.”
Chris Evans, an actor best known for playing Captain America in the Marvel films, said: “Justice. Sending love to George Floyd’s family and friends.”
Scandal actor Kerry Washington wrote: “A guilty #verdict. But this fight for justice is not over. We have a lot of work to do. There is more fight ahead of us.”