Olivier Grouillard (French pronunciation: [ɔlivje grujaʁ]; born 2 September 1958) is a French racing driver, who competed in Formula One from 1989 to 1992, and IndyCar in 1993.

Born in Fenouillet, Haute-Garonne, Grouillard started kart racing from the age of fourteen competing in events such as the Volant Elf. He progressed to Formula Renault winning the title before Grouillard competed in F3000 from 1985 to 1988 taking two wins. He also participated in the Birmingham Superprix but did not start the race.

In 1989, Grouillard joined the Ligier Formula One team before joining the Osella team for 1990 and 1991 when the team was renamed Fondmetal. His last season came in 1992, when Grouillard drove for Tyrrell. He left the sport following the year without receiving offers for a drive in 1993.

After leaving Formula One, Grouillard raced in the CART PPG World Series, competing in the Indianapolis 500 for which he did not qualify but showed consistency. Grouillard became well known for driving in Sports Cars between 1994 and 2001 having success. During his time in Sports Cars, he raced in the BPR Global GT Series, the FIA GT Championship, the Daytona 24 Hours, the Le Mans 24 Hours and the American Le Mans Series. He retired from motorsport at the end of 2001.

Grouillard was born, in Fenouillet. He started racing karts from the age of 14 and competed in the Volant Elf in 1981 and progressed to Formula Renault in 1982 and took the title. In 1983, Grouillard went into French F3 and drove for the ORECA team racing a Martini Mk39 Alfa Romeo to finish 4th scoring 33 points. Driving a Martini Mk42 in 1984 brought him the title and scored 108 points. For 1985, Grouillard competed in the inaugural season of F3000 spending the year mostly confined to qualifying in the midfield but delivered good races along with reliability. In 1986, he left ORECA to join Formula Team Ltd driving a Lola T86/50 Cosworth. At Mugello, Grouillard finished fourth despite taking an early lead. At the Osterrichring, he took sixth and overall scored four points despite limited participation as the team was short on funding. Grouillard returned to ORECA for 1987 in a March 87B Cosworth. His performances dropped despite having impressive qualifying record throughout the season. For 1988, Grouillard moved to the GBDA Motorsport driving a Lola T88/50 Cosworth. He once again showed potential during qualifying and was regularly scoring points along with wins. Grouillard was slightly injured in a crash during the 1988 Birmingham Superprix sustaining bruised ankles although observers initially thought that Grouillard had broken both his legs. Grouillard was able to start the race but had to run to the pit lane for the spare car after his car suffered a failure with the engine. Grouillard however, did not start the race.

Grouillard also raced a series of works and semi-works BMW M3's for BMW in the 1987 World Touring Car Championship and the 1988 European Touring Car Championships

Grouillard joined Ligier to fill in the seat left by Stefan Johansson and was the team-mate to René Arnoux for 1989. He qualified 22nd in his first race in Brazil and finished ninth. At Imola, he overcame spinning his car to start in 10th, but was disqualified when mechanics worked on his car during a red flag stint, caused by the accident of Gerhard Berger at Tamburello. He started outside the top-ten at Monaco and Mexico, finishing eighth in the latter but was unable to qualify in Phoenix and Montréal. He started from 17th at his home race at the French Grand Prix and drove to sixth, despite having issues with the tyres and gearbox, scoring his only World Championship point. For the last six races, Grouillard failed to qualify higher than 20th and did not qualify in Portugal. In qualifying for the Belgian Grand Prix at Spa, Grouillard impeded the Lotus of Nelson Piquet by staying on the racing line whilst the Brazilian was on his last flying lap. On the dirty line, Piquet spun off and shook his fist at Grouillard as he passed by. This cost the triple World Champion his chances in qualifying and the race, and it was to be the first of such incidents involving Grouillard's misuse of his mirrors. At Adelaide, he spun which followed a heavy crash in the rain. In fact, for the season ending Australian Grand Prix in Adelaide, he kept the Ligier mechanics busy by spinning off and hitting the concrete walls twice during practice and qualifying as well as in the race morning warm up session (which was wet) and the race.

During his last 2–3 seasons in Formula One, Arnoux had gained the reputation of being a blocker, a driver who rarely used his mirrors and regularly held up others both in qualifying and races. Unfortunately this trait seemed to have been passed on to Grouillard, who was fast gaining his own reputation of being a blocker.