Small Business Comeback Act This bill establishes a recovery compensation program whereby the Department of the Treasury shall authorize specified payments to certain small businesses to support their recovery from the COVID-19 (i.e., coronavirus disease 2019) pandemic. Treasury must appoint a Special Administrator to oversee the recovery compensation program, and the administrator must develop an application form that is simple to file and audit that applicants shall use when seeking recovery compensation. The maximum amount of recovery compensation an applicant may receive shall be the lesser of their average payment for total monthly expenses or $50 million. Among other requirements, an eligible entity must (1) be in an impaired sector as defined by the administrator; (2) have significant operations in, and a majority of its employees based in, the United States; and (3) continue to pay salaries or wages to employees who tested positive for COVID-19 or were exposed to COVID-19 in the workplace. Allowable uses of recovery compensation include (1) payroll costs; (2) costs related to the continuation of group health care benefits; (3) insurance premiums; (4) paycheck protection loan and economic injury disaster loan repayment obligations; and (5) federal, state, and local tax obligations. The bill also establishes the Special Inspector General for COVID-19 Recovery Funds, who shall conduct, supervise, and coordinate audits and investigations of the payment of recovery compensation. The bill further establishes the Congressional Oversight Board, which shall oversee the implementation of the recovery compensation program.