Workplace Religious Freedom Act of 1999

Workplace Religious Freedom Act of 1999 - Amends the Civil Rights Act of 1964 to modify the definition of "religion" to include all aspects of religious observance, practice, and belief unless, after initiating and engaging in an affirmative and bona fide effort, an employer demonstrates that it is unable to reasonably accommodate a religious observance or practice without undue hardship (action requiring significant difficulty or expense) on the conduct of the employer's business.

Prohibits deeming an accommodation by the employer reasonable if the accommodation does not remove the conflict between employment requirements and the religious observance or practice. Excludes, in certain circumstances, a defense that the accommodation would be in violation of a seniority system. Prohibits requiring payment of premium wages for work performed during hours to which premium wages would ordinarily be applicable if work is performed during those hours only to accommodate religious requirements of an employee.