Born in Askim and raised in Spydeberg, Solberg inherited an enthusiasm for motorsport from his parents, who competed in bilcross — a popular Norwegian grassroots rallycross format. He won a nationwide RC car championship in 1987 at the age of 13 and entered his first competitive bilcross event in 1992, the same week he received his driving licence. By the mid-1990s he had won the Norwegian rallycross championship and the Norwegian hillclimb championship in both 1995 and 1996, claiming 19 of 21 events in 1995 alone.
In 1998 he became the Norwegian Rally Champion, and his talent attracted attention from the World Rally Championship's factory teams. With the aid of compatriot John Haugland he secured a junior pilot role with the Ford Motor Company for three years from 1999. His debut on the Safari Rally that year — stepping in for an injured Thomas Rådström — produced a fifth-place finish and his first points in the WRC.
In 2000 Solberg left Ford to join the Subaru World Rally Team, whose lineup then included Richard Burns and Juha Kankkunen. His first WRC podium came at the Acropolis Rally in 2001, the same year he deliberately dropped positions in Corsica to support teammate Burns's championship bid.
His breakthrough win arrived at the 2002 Wales Rally GB, capitalising on a Marcus Grönholm accident. The 2003 season brought his world title: entering the final round — again the Wales Rally GB — in a three-way battle with Sébastien Loeb and Richard Burns, Solberg finished ahead of Loeb to claim the Drivers' Championship, becoming the first Norwegian to win a WRC drivers' world title.
Solberg spent the next two seasons finishing as championship runner-up to Loeb, winning five rallies in 2004 and three in 2005, including a third consecutive Wales victory. His 2005 season included a notable retirement in Australia after striking a kangaroo. Following Subaru's withdrawal from the WRC at the end of 2008, Solberg formed his own team — the Petter Solberg World Rally Team — competing in Citroën machinery and later returning to the Ford factory programme in 2012. His partnership with co-driver Phil Mills, which lasted 152 consecutive events from 1999, produced 13 rally victories and one world title before Mills's retirement from co-driving in 2010.
Solberg switched to rallycross for the 2013 season, competing in the FIA European Rallycross Championship. In 2014 he became the inaugural winner of the FIA World Rallycross Championship with a PSRX Citroën DS3 Supercar, and successfully defended the title in 2015. He thereby became the first driver in history to hold FIA World Championship titles in two different disciplines.
From 2017 he partnered with Volkswagen Motorsport to create PSRX Volkswagen Sweden, driving the Polo GTi RX. The team became the dominant force in World RX, claiming the Team's Championship in both 2017 and 2018. Across 24 events in those two seasons the PSRX squad won 19 of them. Solberg retired from full-time competition at the end of 2018 but completed a farewell tour in 2019 that included wins at Gymkhana Grid and the final WRC class win at the 2019 Wales Rally GB.
Solberg is the younger brother of fellow WRC driver Henning Solberg, who won the Norwegian Rally Championship five times consecutively from 1999 to 2003. He is married to Swedish driver Pernilla Solberg, daughter of former Volvo factory driver Per-Inge Walfridsson. Their son Oliver Solberg has competed in the World Rally Championship, and the family has twice won the Race of Champions Nations Cup for Team Norway together.
After his retirement from full-time motorsport, Solberg was diagnosed with ADHD. He has remained a visible figure in the motorsport world as a supporter of his son's career and as a participant in exhibition events.
Petter Solberg's twin world championship haul — WRC in 2003 and WRX in 2014 — places him in exclusive company. His ability to succeed at the highest level across two technically distinct forms of motorsport, combined with his charisma and the "Mr. Hollywood" persona that made him a fan favourite, ensure his standing as one of the most distinctive careers in twentieth and twenty-first century rally motorsport.