Antonio Pizzonia (from Manaus, Brazil) is one of two test drivers for the Williams Formula One team; during the 2004 season he drove in 4 races as an emergency replacement for Ralf Schumacher.

From 1991 to 1996 he competed in various karting series. In 1997 he moved to Britain and competed in Formula Vauxhall Junior; Pizzonia placed second, and won the Winter Festival. In 1998, in addition to taking the Championship in F-Vauxhall Junior, he won the Formula Renault Winter Festival. His 1999 season was even more successful, winning the British F-Renault series and finishing second in its European counterpart. In 2000, Pizzonia took 3 wins on his way to the British Formula Three championship.

For 2001, Pizzonia switched to the Formula 3000 series, winning one race and finishing 2nd in the championship. He was then hired as test driver for Williams; however, he continued in F3000, placing 8th. In 2003 Pizzonia was hired by the Jaguar F1 team to partner Mark Webber. Following a string of poor results, he was dropped midway through the season and replaced by Minardi's Justin Wilson. In 2004 he returned to Williams as test driver. Before the German Grand Prix, it was announced that Pizzonia would take over for Marc Gené, who had been filling in for the injured Ralf Schumacher. At the German Grand Prix, he finished 7th to take his first 2 career points; he repeated the feat at the Hungarian Grand Prix. In Belgium, he led an F1 race for the first time, but failed to finish the race due to mechanical problems. He claimed a further 2 points in Italy, but with the announcement of Ralf Schumacher's return for the Chinese Grand Prix, Pizzonia has almost certainly driven his final race of the season. Prior to the 2005 season, Pizzonia was in a virtual shoot-out with German Nick Heidfeld for the second race seat alongside Webber. Despite Pizzonia's experience with the team and financial support from Petrobras, Heidfeld was given the seat. Pizzonia is still employed at Williams as a test driver.

Complete Formula One results

(Note: grands prix in bold denote points scoring races.)