Jarrett was introduced to cars early; his father allowed him to drive to church at age nine. He entered his first race in 1952 at Hickory Motor Speedway, driving a Sportsman Series Ford he co-owned with his brother-in-law, and finished tenth. He began his Grand National career at the 1953 Southern 500 at Darlington Speedway, won the NASCAR Late Model Sportsman National championships in 1957 and 1958, and was the 1955 track champion at Hickory Motor Speedway.
In 1959 Jarrett purchased a Junior Johnson Ford for $2,000, entering two races immediately to cover the cost. He won five races in 1960. The 1961 Grand National championship followed, built on 22 top-five finishes and 34 top-ten finishes across 46 races. In 1964 he joined team owner Bondy Long with Ford backing, winning 15 races, though the championship went to Richard Petty. The following year Jarrett had his best season: 13 wins and a second Grand National championship, placing in the top five in 42 of 54 races. His 1965 Southern 500 win at Darlington was by 14 laps and 2 car lengths — a margin of 19.25 miles, the largest victory margin in NASCAR history in terms of distance. When Ford withdrew from NASCAR in 1966, Jarrett retired from driving at age 34, the only driver to retire as the reigning NASCAR champion.
Jarrett began his broadcasting life in the early 1960s with a taped radio program on WNNC in Newton, North Carolina. In 1978 he became a radio broadcaster for MRN Radio. A highlight of his radio work came on July 4, 1984, when he interviewed President Ronald Reagan live at the Firecracker 400 at Daytona International Speedway, the race in which Richard Petty claimed his 200th win. Jarrett hosted the daily MRN program Ned Jarrett's World of Racing until May 15, 2009.
On television, Jarrett worked as a pit reporter for CBS from 1979 to 1984 and as color analyst from 1984 to 2000, while also serving as color analyst for ESPN from 1988 to 2000. His most celebrated moment as a broadcaster came at the 1993 Daytona 500, when CBS producer Bob Stenner encouraged Jarrett to abandon impartiality on the final lap as his son Dale Jarrett battled Dale Earnhardt. Jarrett openly coached his son home, saying "It's the Dale and Dale show, and you know which Dale I'm pulling for!" When Jarrett attempted to apologize to Earnhardt afterward, Earnhardt replied, "I'm a father, too." He had also called Dale's first victory in the 1991 Champion Spark Plug 400 at Michigan International Speedway. Jarrett was a host for Inside Winston Cup Racing on TNN and NASCAR Tech on FSN.
In 2015 and subsequent years, Jarrett returned to the Darlington throwback broadcasts for part of the Southern 500 alongside his son Dale and broadcaster Ken Squier.
Ned and Dale Jarrett became only the second father-son combination to win NASCAR Cup championships, after Lee Petty and Richard Petty. Dale won the Winston Cup championship in 1999 and later became a broadcaster for NBC Sports. Ned's son Glenn Jarrett drove sporadically in the Busch Series before also becoming a racing broadcaster. Dale's son Jason Jarrett had starts in the Busch and Cup Series and won in the ARCA Re/Max Series. Ned's daughter Patti is married to Jimmy Makar, who served as crew chief for Bobby Labonte's 2000 championship season at Joe Gibbs Racing.
Jarrett was inducted into the Motorsports Hall of Fame of America in 1997 and the NASCAR Hall of Fame in 2011. He was named one of NASCAR's 50 Greatest Drivers in 1998 and one of NASCAR's 75 Greatest Drivers in 2023. By 2004 he had been inducted into 12 motorsports and sports halls of fame.
Jarrett died at his home in Newton, North Carolina, on June 4, 2026, at the age of 93.