What is the largest us dollar currency note?

The largest denomination US banknote currently circulating is the $100 note. There used to be $500, $1000, $5000 and $10000 notes also, but they were phased out several decades ago because they made it easy for criminals to transfer large amounts of illegal funds.

There was also a $100,000 note intended for transfers between Federal Reserve banks (it never was in general circulation, and in fact it would have been illegal for a private individual to have one, since it was a gold certificate).