The Ohio Apportionment Board was an administrative body which drew the single-member legislative districts for the Ohio General Assembly every ten years following the census from 1851 to 2011. Each of the 33 senate districts is composed of three contiguous of the 99 house of representatives district.

The board had five members:

• the Governor of Ohio,
• the Ohio Secretary of State,
• the Ohio State Auditor,
• a member selected by the Speaker of the Ohio House of Representatives and the senate leader of the same party.
• a member selected by the house and senate leaders of other party.

The members selected by the legislators were added when voters amended Article XI of the Ohio Constitution in 1967. This format ensured that no party can hold all five seats and at least one seat would belong to the minority party.

In 2011, the board's members were:

• Gov. John Kasich (R)
• State Auditor Dave Yost (R)
• Secretary of State Jon A. Husted (R)
• Assembly Republican Member: Senator Tom Niehaus (R), and
• Assembly Democratic Member: Representative Armond Budish (D)

Democrats controlled the apportionment board in 1971 and 1981. Republicans controlled the apportionment board in 1991, 2001 and 2011.

Following the 2011 redistricting cycle and resulting legislative gridlock, the he board was replaced by the Ohio Redistricting Commission following the passage of a constitutional amendment in 2015.