The 2004 United States Grand Prix (officially the 2004 Formula 1 United States Grand Prix) was a Formula One motor race held on June 20, 2004, at the Indianapolis Motor Speedway in Speedway, Indiana. It was Race 9 of 18 in the 2004 FIA Formula One World Championship.

Rubens Barrichello started from pole position in his Ferrari ahead of teammate Michael Schumacher. However, following a start-line incident between five cars, four of whom retired as a result, Schumacher overtook Barrichello on the safety car restart on lap six, and despite a threat from Barrichello after the final pit stops, Schumacher held on to take his eighth win of the season. Takuma Sato became only the second Japanese driver to achieve a podium finish after Aguri Suzuki. This was Takumo Sato's only podium finish in F1.

The race saw two serious accidents caused by Michelin tire failures in what would be a precedent for the 2005 United States Grand Prix, at which all Michelin-shod cars withdrew over safety concerns. First, Fernando Alonso's Renault crashed into the barriers alongside the end of the pit straight on lap nine. Later, Ralf Schumacher's Williams suffered the same fate, but in the most dangerous part of the track, causing him to hit the wall at a ninety-degree angle rearwards. The impact left Schumacher with spinal fractures and concussion, which prevented him from racing until the 2004 Chinese Grand Prix, three months later.

This was the last US Grand Prix race that featured a US-owned Formula One team until 2016 when Haas debuted as newly-formed US Formula One team.

Heading into round nine, the season had so far belonged to Michael Schumacher, driving for Ferrari, winning all but one race, in Monaco, owing to a crash with Juan Pablo Montoya, and so had 70 points out of a possible 80. However, Rubens Barrichello, Schumacher's teammate at Ferrari, was only 16 points behind him, having taken six podiums and two other points finishes. In the Constructors' Championship, however, Ferrari were dominating, with 124 points: more than double that of second-placed Renault, the only other team to win a Grand Prix that year so far, with Jarno Trulli triumphing in Monaco. Third-placed BAR had a quick car, but suffered reliability problems. Lead driver Jenson Button, like his future teammate Barrichello, picking up six podiums and two other points finishes. However, of the eight races so far, Takuma Sato, in the other BAR, had suffered five engine failures, three of which had occurred in the preceding three Grands Prix in Monaco, Europe, and Canada.

Williams and Toyota had been disqualified from the last event in Canada for illegal brake ducts, even though, in Williams's case, this proved to be a manufacturing error and had not given them any aerodynamic or cooling gain.

The bottom 6 teams in the 2003 Constructors' Championship were entitled to run a third car in free practice on Friday. These drivers drove on Friday but did not compete in qualifying or the race.

Four practice sessions were held before qualifying - two 60-minute sessions on Friday and two 45-minute sessions on Saturday. All of the teams, with the exception of Ferrari, Williams, McLaren, and Renault, were permitted to run three drivers on Friday. Rubens Barrichello topped the timesheets in practices one, two, and three, with times of 1:11.354, 1:10.365, and 1:10.911 respectively. Jenson Button, driving for BAR, however, prevented Barrichello from a clean sweep in the second Saturday session: his time of 1:10.056 was 0.143 quicker than second-placed Michael Schumacher. Third was Takuma Sato, Button's teammate, whilst Barrichello languished in fourth. However, despite the pace of the Ferraris, their Bridgestone tires had grained in the long runs, meaning that balls of rubber would form on the surface of the tire, reducing mechanical grip.