Sato began karting in Japan at age nineteen, winning the national karting title in 1997. With Honda's backing he moved to Europe in 1999, making his British Formula Three debut mid-season with Diamond Racing in Class B before graduating to the top class with Carlin Motorsport in 2000. He took four wins and finished third in the championship. In 2001 he dominated the series, winning twelve of twenty-six races to become the first Japanese driver to claim the British Formula Three title. He also won the prestigious Macau Grand Prix and Masters of Formula 3 non-championship events that year.
Sato made his Formula One debut with the Honda-powered Jordan team in 2002, paired with Giancarlo Fisichella. His season included a severe accident in Austria when Nick Heidfeld's Sauber struck the side of his cockpit. Despite showing flashes of pace, his year ended with a fifth place at his home Grand Prix at Suzuka.
As Honda focused its Formula One investment entirely on British American Racing, Sato joined BAR as a test driver for 2003. He replaced Jacques Villeneuve for the final round at Suzuka, scoring sixth after a battle with Michael Schumacher. He was retained as a full-time driver for 2004.
The 2004 season was Sato's peak in Formula One. He qualified four times in the top three, including a front row start at the European Grand Prix where he also set the circuit's overall lap record. At the United States Grand Prix, after BAR declined to pit under safety car conditions, Sato launched an aggressive recovery drive with overtaking moves that earned him his only Formula One podium — third place. It was the first podium for a Japanese driver since Aguri Suzuki at the 1990 Japanese Grand Prix. Sato finished eighth in the Drivers' Championship with 34 points — the best championship result by a Japanese driver in Formula One history — and helped BAR-Honda to second in the Constructors' standings.
In 2005, a more competitive midfield made progress harder. Sato and his teammate were disqualified from the San Marino Grand Prix and the team was banned from the following two races when their cars were found underweight after fuel removal, a ruling the team disputed. The season never recovered and Sato was not retained when Honda took full control of BAR.
Sato joined the new Super Aguri F1 team for 2006, a Honda-supported outfit founded by former driver Aguri Suzuki. The team's opening half of the year relied on a modified 2002 Arrows A23 chassis. Despite the limitations, Sato's professionalism and competitive spirit drew positive attention. A new car introduced at the German Grand Prix improved pace, and Sato finished tenth in Brazil at season's end.
Super Aguri ran a reworked Honda RA106 in 2007 and improved markedly. Sato progressed to Q3 at Australia and scored the team's first championship point in Spain. At the Canadian Grand Prix he passed Kimi Räikkönen and closed to fifth before a pit stop error dropped him back; he recovered to sixth, including a pass on Fernando Alonso's McLaren on lap 67 that earned him F1 Racing magazine's Overtake of the Year award.
Financial difficulties restricted Super Aguri's 2008 programme from the outset, and the team withdrew from the championship after the Spanish Grand Prix, ending Sato's Formula One career mid-season.
After a year away from racing, Sato entered the IndyCar Series with KV Racing Technology in 2010. He improved steadily and scored two pole positions in 2011. Racing for A.J. Foyt Enterprises from 2013, he took his first IndyCar victory at the Grand Prix of Long Beach — the first IndyCar win by a Japanese driver.
Sato joined Andretti Autosport in 2017. At the Indianapolis 500 that year, he won from the front, becoming the first Asian driver to win the event. The following year, now back at Rahal Letterman Lanigan Racing, he won at Portland and continued adding victories through 2019, winning at Barber Motorsports Park and Gateway. On 23 August 2020, qualifying on the outside of the front row, Sato won the Indianapolis 500 for a second time — a landmark achievement that secured his place among the race's most celebrated modern competitors.
Sato joined Dale Coyne Racing in 2022 and moved into a part-time oval programme with Chip Ganassi Racing in 2023 before returning to Rahal Letterman Lanigan Racing for Indianapolis 500-only appearances from 2024 onward. At the 2025 Indianapolis 500 he led 51 laps — the most of any driver — and qualified second on the front row before finishing ninth following disqualifications of other competitors.
Sato's Formula One career established him as the most successful Japanese driver in the championship to that point, with his 2004 eighth-place championship finish a record for a Japanese driver. His subsequent IndyCar career delivered two Indianapolis 500 victories and multiple race wins, cementing a reputation built on decisive overtaking and unconditional commitment to attack. His aggressive approach and consistent proximity to victory at Indianapolis — combined with his 2013 Long Beach win as the series' first Asian victor — established him as one of the most celebrated international drivers in IndyCar history. His son Rintaro Sato made his racing debut in the 2024 F4 Japanese Championship.