United States labor law sets the rights and duties for employees, labor unions, and employers in the US. Labor law's basic aim is to remedy the "inequality of bargaining power" between employees and employers, especially employers "organized in the corporate or other forms of ownership association". Over the 20th century, federal law created minimum social and economic rights, and encouraged state laws to go beyond the minimum to favor employees. The Fair Labor Standards Act of 1938 requires a federal minimum wage, currently $7.25 but higher in 29 states and D.C., and discourages working weeks over 40 hours through time-and-a-half overtime pay. There are no federal laws, and few state laws, requiring paid holidays or paid family leave. The Family and Medical Leave Act of 1993 creates a limited right to 12 weeks of unpaid leave in larger employers. There is no automatic right to an occupational pension beyond federally guaranteed Social Security, but the Employee Retirement Income Security Act of 1974 requires standards of prudent management and good governance if employers agree to provide pensions, health plans or other benefits. The Occupational Safety and Health Act of 1970 requires employees have a safe system of work.

Labor unions represent United States workers in many industries recognized under US labor law since the 1935 enactment of the National Labor Relations Act. Their activity today centers on collective bargaining over wages, benefits, and working conditions for their membership, and on representing their members in disputes with management over violations of contract provisions. Larger labor unions also typically engage in lobbying activities and electioneering at the state and federal level.