No they are not. Money is always taxed when it changes ownership, as corporations are legal persons, it pays taxes on its profit. When shareholders are given some of that profit via dividends, that money is again changing ownership so it taxed as income to those shareholders. Saying something is double taxed is to misunderstand "when" tax applies. If you don't want company earnings taxed that way, don't be a C corp, but it isn't double taxing.