Muhammad Ali, the boxing legend who famously dubbed himself "The Greatest of All Time," died Friday at age 74 at a Phoenix-area hospital after 32 years of living with Parkinson's disease.
Even as he became more ill over the years, Ali's name remained one of the most well-known in the world. "Muhammad Ali" continued to evoke superhuman strength and courage, and the three-time world champion's dedication to philanthropic causes only served to elevate his reputation further.
It comes as no surprise, then, that he was mourned so widely on social media after his death Friday. Celebrity tributes included words and images from Madonna, Caitlyn Jenner, Mike Tyson and J.K. Rowling, among others.
We've rounded up several of the most poignant celebrity reactions below.
Manny Pacquiao
J.K. Rowling
Quincy Jones
In a statement, Jones said: "RIP to the greatest of all time, our brother and friend Muhammad Ali. A man of character, faith, dignity, humanity and professionalism in your craft, you embodied the best of us as human beings. The world will miss your presence, but we'll celebrate your spirit forever."