Redistricting in the United States is the process of drawing electoral district boundaries. For the United States House of Representatives, and state legislatures, redistricting occurs after each decennial census.

The U.S. Constitution in Article 1, Section 2, Clause 3 provides for proportional representation in the House of Representatives. The Reapportionment Act of 1929 required that the number of seats in the U.S. House of Representatives be kept at a constant 435, and a 1941 act made the reapportionment among the states by population automatic after every decennial census. Reapportionment occurs at the federal level followed by redistricting at the state level. According to Colegrove v. Green, 328 U.S. 549 (1946), Article I, Section 4 left to the legislature of each state the authority to establish congressional districts; however, such decisions are subject to judicial review. In most states redistricting is subject to political maneuvering, but some state legislatures have created independent commissions.

The Uniform Congressional District Act (enacted in 1967) requires that representatives be elected from single-member districts. When a state has a single representative, that district will be state-wide.

Gerrymandering in the redistricting process has been a problem since the early days of the republic. In recent years, critics have argued that redistricting has been used to neutralize minority voting power. Supporters say it enhances electoral competitiveness.