Occupational Safety and Health-Fairness Act of 2003

Exempts employers from a 15-day deadline for notifying the Secretary of Labor of their intent to contest OSHA citations, notices of uncorrected violations, and proposed penalties, if their failure to meet such deadline results from mistake, inadvertence, surprise, or excusable neglect.

Limits what may be considered willful violations under OSHA.

Requires the Occupational Safety and Health Review Commission (OSHRC) to give de novo consideration to evidence of the penalty's appropriateness with respect to these factors: (1) size and financial condition of the business of the employer; (2) gravity of the violation, considering probability of harm, nature and extent of the harm, number of affected employees, and other relevant factors; (3) employer's good faith, including efforts to comply or abate; (4) history and recentness of substantially similar previous violations of the cited employer at the same nonconstruction worksite and construction worksites in the same State; and (5) the employer's, employees', or other persons' degree of responsibility or culpability for the violation.

Increases OSHRC membership from three to five.

Awards attorney's fees and costs to a prevailing employer in an administrative adversary adjudication, or a judicial review of an action, instituted under OSHA, if at the time such adjudication was initiated or such action filed the employer had not more than: (1) 100 employees; and (2) $1,500,000 net worth.

Revises judicial review provisions to require deference to be given to reasonable OSHRC conclusions with respect to all questions of law.