Sex discrimination involves treating someone (a job applicant or employee) unfavorably because of that person's sex. Sex discrimination is a form of employment discrimination that violates federal law—including Title VII of the Civil Rights Act of 1964 (42 U.S.C. §2000e).

In addition to these federal laws, states also have laws against sex discrimination in employment. These state laws are generally located in a state’s statutes—often in the labor code or employment-related statutes.

Discrimination against an individual because of gender identity—including transgender status or sexual orientation—is discrimination because of sex in violation of Title VII.

The law forbids discrimination when it comes to any aspect of employment, including hiring, firing, pay, job assignments, promotions, layoff, training, fringe benefits, and any other term or condition of employment.

For the regulations related to sex discrimination, see the Code of Federal Regulations, beginning with 29 CFR 1604.1.

In Wisconsin, sex discrimination in employment is prohibited under both federal and state law. Federally, Title VII of the Civil Rights Act of 1964 makes it illegal to discriminate based on sex in any aspect of employment, which includes hiring, firing, pay, promotions, and other terms and conditions of employment. This federal protection extends to gender identity and sexual orientation. At the state level, the Wisconsin Fair Employment Act (Wis. Stat. § 111.31 - § 111.395) also prohibits employment discrimination on the basis of sex, sexual orientation, and gender identity, among other protected characteristics. Employers in Wisconsin must comply with these laws and ensure that their employment practices do not discriminate against individuals based on sex. Violations of these laws can lead to legal consequences, and individuals who believe they have been discriminated against may file a complaint with the Equal Rights Division of the Wisconsin Department of Workforce Development or the federal Equal Employment Opportunity Commission (EEOC).