I doubt there's anyone more famous. I couldn't pick Messi out of a lineup because I don't follow soccer, and just know him from the "Jews did this" meme.
For any athlete there are plenty of people who don't follow that sport, and for music the most famous would be some kind of pop music that is mostly aimed at people under 30, but there's not likely anybody over 5 years old in the US, or anybody over like 12 in the developed world who doesn't know who the US president is, though technically almost nobody knew who the actual US president was for the last 4 years.