Stop CEO Excessive Pay Act The bill amends the Internal Revenue Code, with respect to the deduction for trade or business expenses, to prohibit a deduction for excessive compensation for any employee of the taxpayer. "Excessive compensation" is the amount by which the compensation for services performed by an employee during the year exceeds the lesser of: (1) the median of the compensation paid for services performed by all employees of the taxpayer during the taxable year, multiplied by 25; or (2) $1 million. The bill amends the Securities Exchange Act of 1934 to: (1) prohibit an issuer from paying excessive compensation to an employee unless the compensation is approved by at least 50% of the shareholders, and (2) impose monetary penalties on issuers that violate the requirement. The bill also prohibits tax deductions for penalties paid to the Securities and Exchange Commission pursuant to this bill.