The Wisconsin Fair Employment Act prohibits employers from discriminating against applicants and employees on the basis of age, race, creed, color, disability, marital status, sex, national origin, ancestry, sexual orientation, criminal records, genetic test results, military service, or the off-duty use or nonuse of lawful products away from the employer's premises. In addition, employers are prohibited from using discriminatory statements, advertisements, publications, preemployment inquiries, and other selection or testing practices. The Act covers all employers, regardless of size (WI Gen. Stat. Sec. 111.31et seq.).
There is additional information on specific practices.