Thierry Marc Alain Boutsen (French: [tjɛ.ʁi but.sɛn]; born 13 July 1957) is a Belgian former racing driver, businessman and motorsport executive, who competed in Formula One from 1983 to 1993. Boutsen won three Formula One Grands Prix across 11 seasons.

Boutsen competed in Formula One for Arrows, Benetton, Williams, Ligier and Jordan. He finished fourth in the 1988 World Drivers' Championship with Benetton. Boutsen also competed in 10 editions of the 24 Hours of Le Mans from 1981 to 1999, finishing runner-up in 1993 and 1996 with Peugeot and Porsche, respectively.

Since retiring from motor racing, Boutsen has moved into the aviation industry, selling business jets from his firm in Monaco. He is also the founder, co-owner and advisor to Boutsen Racing, who have competed in touring car racing since 1998.

After winning the "Volant V" in 1977 at the André Pilette Racing School, Zolder, Boutsen entered the Belgian Formula Ford 1600 championship and won it in 1978 with 15 victories in 18 races. He also entered the 1978 Spa 24 Hours race, the last auto race on the old 14 km (8.7 mi) Spa-Francorchamps circuit- driving a Toyota Trueno. For 1979, he moved to Formula 3, winning three races in 1980 and second place in the European title race, behind Michele Alboreto. In 1981, he moved to Formula 2 and was again second in the European championship, including winning at the 14-mile Nürburgring- this time behind Geoff Lees.

Boutsen also entered the 1981 24 Hours of Le Mans. The race started at 3pm in unusually hot weather – one hour earlier than usual due to the Parliamentary elections held on the same weekend. At 4:06pm Boutsen suffered a massive accident just after the Hunaudières kink, some 400 metres (0.25 mi) before the Mulsanne bosse (the "hump") when his WM P81-Peugeot was travelling at some 350 km/h (217 mph). A suspension piece had failed and the car hit the guard-rail losing the entire rear end. Boutsen was untouched, but the debris field of hurled parts and bodywork was spread over 150 metres (490 ft). Three marshals and a gendarme were struck by the debris. One of them, Thierry Mabilat, was killed - struck in the chest by a detached piece of the guard rail. The other two marshals, Claude Hertault and Serge David (who lost an arm), and the gendarme were all seriously injured.

In 1983, Boutsen drove in the European Touring Car Championship and in World Sportscar races, where he won the very first Group C race, the Monza 1000 km with Bob Wollek driving a Porsche 956. He also won the famous Daytona 24-hour race in 1985, co-driving the Porsche 956 from the Preston Henn Racing with Bob Wollek, A. J. Foyt and Al Unser Sr.

Boutsen was considered a promising driver, testing for McLaren and Brabham. He was briefly attached to the Spirit Honda F1 project before losing out to his Formula Two teammate Stefan Johansson.

In 1983, Boutsen paid $500,000 for a drive in Formula One and made his debut with Arrows at his home race, the 1983 Belgian Grand Prix at the shortened 7 km (4.3 mi) Spa. While he scored no points in 1983, his careful handling and close performance compared to experienced teammate Marc Surer allowed him to foster a positive reputation within the team. With backing from Barclay cigarettes he remained with Arrows for a further three seasons. The first saw Arrows struggle with their difficult first turbocharged car, with powerful BMW turbo engines but poor handling. Boutsen scored points twice in the old Cosworth DFV powered A6 and once in the turbo machine. His second season saw several notable results, including second place at Imola. Boutsen crossed the line third, behind Alain Prost and Elio de Angelis but after the race, Prost was disqualified because his car was 2 kg underweight. Three more points scores saw him 11th overall in the standings. A final season with Arrows saw no points for Boutsen in an uncompetitive car, but in parallel to F1 he drove for the Walter Brun team in Group C and clinched the World Championship title with them in 1986, winning that year's Spa 1000 km.