Born in Menomonie, Wisconsin, Panch relocated to California at a young age and began his motorsport involvement as a car owner in Oakland. When his regular driver failed to appear for a race, he stepped in himself and finished third, discovering a talent he would spend the next two decades developing. Over six years on the West Coast he won a championship and numerous races, including five NASCAR events run on West Coast tracks.
His first eastern NASCAR appearance came at Darlington Raceway in 1953, and NASCAR founder Bill France Sr. subsequently encouraged him to base himself on the East Coast. Lee Petty invited him to race at the 1954 Darlington event, where he finished third. That result attracted the attention of Tom Horbison, who hired Panch for the 1955 season. His performances that year caught the eye of Pete DePaolo, who brought him into the factory Ford team. Panch won his first NASCAR race on July 20, 1956, at Montgomery, starting from pole position and leading from flag to flag.
After Ford ended its factory support mid-1957, Panch joined Holman-Moody and won three more events that season, finishing second in the final championship standings. Three lean seasons with limited opportunities followed before a pivotal moment revived his career.
For the 1961 Daytona 500, legendary mechanic Smokey Yunick offered Panch a ride in a year-old 1960 Pontiac. Panch accepted and won the race, one of NASCAR's most prestigious events, announcing his return to the front of the field.
The following year he joined the Wood Brothers as part of the Ford factory-sponsored operation, a partnership that would define the peak of his career. Over sixty-nine races for the team across four-plus years, Panch accumulated eight wins and thirty top-three finishes. He remained with the Wood Brothers until a Ford dispute with NASCAR in March 1966 ended the formal factory arrangement.
In February 1963, during a Daytona speed record attempt in a Ford-powered Maserati, Panch crashed and was trapped in his burning car. He was pulled to safety by a group of bystanders that included fellow drivers Tiny Lund, Ernie Gahan, and Bill Wimble, along with Firestone's Steve Petrasek and mechanic Jerry Rayborn. The rescuers were awarded the Carnegie Medal for heroism. While recovering from second and third-degree burns in hospital, Panch asked Wood Brothers owner Glenn Wood to give his Daytona 500 ride to Lund in his stead. Tiny Lund won that 1963 Daytona 500 in the car Panch had been scheduled to drive — a story that has become one of motorsport's most celebrated acts of camaraderie. Lund later said of Panch: "Marvin would have done the same for us."
For the 1966 World 600 at Charlotte, Panch was hired by Petty Enterprises to drive a year-old car. He won the race — his final career victory — with Richard Petty serving as his relief driver during the event. Panch announced his retirement after the National 500 at Charlotte in October of that year, closing a career that had taken him from Oakland dirt tracks to NASCAR's most storied speedways.
Panch was named one of NASCAR's 50 Greatest Drivers in 1998, a selection that cemented his place in the sport's historical canon. He was inducted into the National Motorsports Press Association Hall of Fame in 1987 and the West Coast Stock Car/Motorsports Hall of Fame in its inaugural class in 2002.
Panch's second wife Bettie founded the Women's Auxiliary of Motorsports. Following his 1961 Daytona 500 win, Panch purchased property in Port Orange, Florida, where he settled after retiring. He was found unconscious in his car on December 31, 2015, and was later pronounced dead of natural causes.