Do you need a license for a lemonade stand?

It depends.

If you are on private property, no.

If you are on public property, maybe. Yes if you are an adult, but you can get away with not having one if you are a minor.

For more debate check out: http://www.lemonade-stand.co.uk/blog/do-i-need-a-permit-to-start-a-lemonade-stand/