how well known is Muhammad Ali (boxer) around the world?

Very well known

Arguably the best boxer ever........pretty well known yeah.

Not many places in the World where his face is not known.

He's more popular than butterflies and bees

Well known enough to where I knew who he was

Probably the most widely known athlete in the world. People in third world countries would go watch his fights live at the cinemas before they had TVs.