Wis. Stat. § 111.321: Prohibited bases of discrimination.

Subject to ss. 111.33 to 111.365, no employer, labor organization, employment agency, licensing agency, or other person may engage in any act of employment discrimination as specified in s. 111.322 against any individual on the basis of age, race, creed, color, disability, marital status, sex, national origin, ancestry, arrest record, conviction record, military service, use or nonuse of lawful products off the employer’s premises during nonworking hours, or declining to attend a meeting or to participate in any communication about religious matters or political matters.