2004 United States House of Representatives elections in Oklahoma

Oklahoma is a state in the South Central region of the United States, bordered by Texas on the south and west, Kansas on the north, Missouri on the northeast, Arkansas on the east, New Mexico on the west, and Colorado on the northwest. Partially in the western extreme of the Upland South, it is the 20th-most extensive and the 28th-most populous of the 50 United States. Its residents are known as Oklahomans and its capital and largest city is Oklahoma City.

In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sovereignty with the federal government. Due to this shared sovereignty, Americans are citizens both of the federal republic and of the state in which they reside. State citizenship and residency are flexible, and no government approval is required to move between states, except for persons restricted by certain types of court orders.

The United States House of Representatives is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together, they comprise the national bicameral legislature of the United States.

The United States census of 2000, conducted by the Census Bureau, determined the resident population of the United States on April 1, 2000, to be 281,421,906, an increase of 13.2 percent over the 248,709,873 people enumerated during the 1990 census. This was the twenty-second federal census and was at the time the largest civilly administered peacetime effort in the United States.

The 2004 United States presidential election was the 55th quadrennial presidential election, held on Tuesday, November 2, 2004. The Republican ticket of incumbent President George W. Bush and his running mate incumbent Vice President Dick Cheney were elected to a second term, defeating the Democratic ticket of John Kerry, a United States senator from Massachusetts and his running mate John Edwards, a United States senator from North Carolina. As of 2020, this is the only presidential election since 1988 in which the Republican nominee won the popular vote. Due to the higher turnout, both major party nominees set records for the most popular votes received by a major party candidate for president; both men surpassed Reagan's record from 20 years earlier. At the time, Bush's 62,040,610 votes were the most received by any nominee for president, although this record would be broken four years later by Barack Obama. Bush also became the only incumbent president to win re-election after previously losing the popular vote.

The 2004 United States Senate elections were held on November 2, 2004, with all Class 3 Senate seats being contested. They coincided with the re-election of George W. Bush as president and the United States House election, as well as many state and local elections. Senators who were elected in 1998, known as Senate Class 3, were seeking re-election or retiring in 2004.

The 2004 United States Senate election in Oklahoma took place on November 2, 2004. The election was concurrent with elections to the United States House of Representatives and the presidential election. Incumbent Republican U.S. Senator Don Nickles decided to retire instead of seeking a fifth term. Republican nominee Tom Coburn won the open seat.

The 2004 United States House of Representatives elections were held on November 2, 2004 to elect all 435 seats of the chamber. It coincided with the re-election of President George W. Bush as well as many Senate elections and gubernatorial elections. Prior to the election in the 108th Congress, Republicans held 227 seats, Democrats held 205, with two Republican vacancies and one independent. As a result of this election, the 109th Congress began composed of 232 Republicans, 201 Democrats, one independent, and one vacancy.