Hall was born in Abilene and raised in Colorado and New Mexico. While studying engineering at the California Institute of Technology, he began racing in local sports car events. He became involved with his older brother Dick at Carroll Shelby Sport Cars in Dallas, where he developed as a driver. His abilities drew international attention at the 1960 United States Grand Prix at Riverside, where he ran a surprising fifth for much of the race in a past-its-prime Lotus-Climax before a mechanical failure intervened. Competition Press noted that "Texas has another international caliber driver ready to take Carroll Shelby's place."
At Riverside, Hall was approached by California car builders Troutman and Barnes seeking funding for a new road racer. Hall backed the project and named the vehicle Chaparral, taking wins with the Chaparral 1 before setting out to build a successor himself.
Hall's Chaparral 2A, built in Midland, Texas during 1962 and 1963, proved a revelation on debut. At its first race — the 1963 Los Angeles Times Grand Prix — Hall put it on pole over a field including Jim Clark, Graham Hill, John Surtees, Dan Gurney, and A.J. Foyt before an electrical fire ended his race.
During 1964 and 1965, Hall and partner Hap Sharp dominated American sports car racing with a dominance rarely seen before or since. In 1965 alone, across 22 starts in major races against top international competition, Chaparrals collected 16 wins and 16 fastest laps. Hall won the 1964 USRRC title outright. At the 1965 12 Hours of Sebring, Hall and Sharp qualified nine seconds faster than the previous year's pole time set by reigning World Champion John Surtees in a factory Ferrari — then overcame factory-backed Fords driven by Dan Gurney, Ken Miles, Bruce McLaren, and Richie Ginther, plus a factory Ferrari driven by Pedro Rodriguez and Graham Hill, to win.
Hall drove briefly in Formula One in 1963 for the British Racing Partnership, accumulating three World Championship points with a best finish of fifth at the German Grand Prix at the Nürburgring.
Hall's driving career came to a premature end at the 1968 Can-Am season finale at Las Vegas. While attempting to unlap himself from Lothar Motschenbacher, the latter's McLaren suffered a catastrophic suspension failure; Hall's Chaparral 2G launched over the stricken car at over 100 mph and crashed into the desert. Hall survived but sustained severe knee injuries that took six months of recovery before he could walk. He made a brief return during the 1970 Trans-Am season but could no longer sustain his previous pace over a race distance.
Possibly no designer of the second half of the 20th century has had more enduring influence on racing car design. Hall pioneered wings, movable aerodynamic devices, side-mounted radiators, semi-automatic transmissions, and composite monocoque chassis — all later adopted and still present in every Formula 1 car.
The Chaparral 2A featured a composite monocoque chassis built with advanced fiberglass technology sourced from the aerospace industry, specifically techniques used on the Convair B-58 Hustler bomber. The chassis was approximately four times stiffer than leading sports cars of the day.
The Chaparral 2E, prepared for the inaugural 1966 Can-Am season, introduced a massive articulated wing mounted on tall pillars above the rear deck, connected via a cockpit pedal to an adjustable nose duct. Because the semi-automatic Chaparrals only needed a throttle and brake pedal, the driver's left foot was free to operate the downforce control. Driver Phil Hill described the effect: "With the wing, you could out-brake everybody, you could out-corner everybody, you could drive under them."
Hall's final Can-Am challenger, the 1970 Chaparral 2J, used a snowmobile engine to power two fans creating constant suction between the car's underside and the road — the world's first constant-downforce racing car. At the 1970 Riverside Can-Am, the 2J qualified more than two seconds faster than the championship-winning McLaren M8D. Though banned after lobbying by rival teams, the concept was copied eight years later by Brabham designer Gordon Murray in the BT46B.
In 1979, Hall brought ground-effect tunnel technology to IndyCar racing with the Chaparral 2K, designed by John Barnard. The car dominated the 1979 Indianapolis 500 in Al Unser's hands until a transmission failure; it returned in 1980 to win both the Indianapolis 500 and the CART PPG Indy Car World Series championship with Johnny Rutherford.
Following his driving career, Hall partnered with Carl Haas to form Haas-Hall Racing. The team was virtually unstoppable in Formula 5000 and the second-generation Can-Am, winning seven consecutive series titles between 1974 and 1980 with Brian Redman and others. In 1978, in their initial season of Indy car competition, Haas-Hall became the first and still only team to win IndyCar racing's Triple Crown — the Indianapolis 500, the Pocono 500, and the California 500.
After the Chaparral 2K era, Hall continued in IndyCar racing with customer chassis, collecting further wins with drivers including John Andretti and Gil de Ferran before retiring from the sport after the 1996 campaign.
Hall was inducted into the Motorsports Hall of Fame of America in 1994 and the International Motorsports Hall of Fame in 1997. An entire wing of the Permian Basin Petroleum Museum in Midland is devoted to Hall and the Chaparral story, housing seven restored Chaparral race cars — the 2A, 2D, 2E, 2F, 2H, 2J, and 2K — each maintained in running condition.
At the 2009 American Le Mans Series season finale at Laguna Seca, former driver Gil de Ferran painted his Acura ARX-02a to resemble a Chaparral in tribute, carrying Hall's race number 66. De Ferran put the car on pole and won the race. The downforce revolution Hall began — from adjustable spoilers on the Chaparral 2A through the suction system of the 2J — became part of the design brief for every major form of racing car: Formula 1, IndyCar, Le Mans, NASCAR, World Rally Championship, and more.