Whose picture is on the US 5000 dollar bill?

James Madison, 4th President of the Unites States, is on the $5,000 bill. Very few of these bills were printed and production was discontinued in 1945. Even though they remain legal to spend they're now collector items and worth much more than $5,000.

US bills higher than $100 are no longer in circulation. They're technically still legal tender but in 1969 President Nixon ordered that banks should no longer distribute high-denomination bills, as a way to limit their use in organized crime.