Avery v. Midland County, 390 U.S. 474 (1968), is a United States Supreme Court case that ruled that local government districts had to be roughly equal in population.

Having already held in 1965 in Reynolds v. Sims that disparities in legislative districts violated the Equal Protection Clause of the Fourteenth Amendment to the United States Constitution, the Supreme Court applied the same logic to local government districts for bodies which also have broad policy-making functions.

The trial court ruled for petitioner that each district under the State's constitutional apportionment standard should have "substantially the same number of people."

It held, however, that the work actually done by the County Commissioners "disproportionately concerns the rural areas" and that such factors as "number of qualified voters, land areas, geography, miles of county roads, and taxable values" could justify apportionment otherwise than on a basis of substantially equal populations.

The five justices who struck down local district inequality based their decision on the precedent in Reynolds v. Sims.