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 Washington State, sex discrimination in employment is prohibited under both federal and state laws. Federally, Title VII of the Civil Rights Act of 1964 makes it illegal to discriminate based on sex in any aspect of employment. This includes hiring, firing, pay, job assignments, promotions, layoffs, training, benefits, and other terms or conditions of employment. Additionally, discrimination on the basis of gender identity or sexual orientation is recognized as a form of sex discrimination under Title VII. At the state level, the Washington Law Against Discrimination (WLAD), found in RCW 49.60, provides similar protections and explicitly prohibits discrimination in employment based on sex, sexual orientation, and gender identity. Employers in Washington are required to comply with both federal and state regulations, and employees who experience sex discrimination have the right to file a complaint with the appropriate state or federal agency.