Ali passed away at the age of 74 on Friday following a long battle with Parkinson's disease, and tributes have poured in from all over the globe, celebrating his life.
And Federer, a 17-time major champion, believes his fellow sporting icon deserves to be commended for all his accomplishments both in and out of the ring.
"The death of Muhammad Ali was definitely a huge shock," Federer said in a media conference ahead of the Stuttgart Open.
"He was one of the greatest athletes there ever was. But he did so much more than just boxing. He had a great personality and endured so much.
"What and how he said things was what people gravitated towards.
"He didn't just have a big mouth, he stood to what he said. In and out of the ring.
"Losing him is very, very sad but at the same time it is nice to see everybody giving so much attention to the wonderful things he achieved."