Langley began racing modified cars in Virginia and Maryland in 1952, entering NASCAR the following year as a driver-owner. He primarily ran the number 64 on his race cars throughout his career. In 1966 he partnered with Henry Woodfield to form Langley-Woodfield Racing, and that season produced the only two race victories of his driving career.
Despite never winning again, Langley was a model of steady points accumulation. He finished fifth in season points in 1969 and 1971, sixth in 1968 and 1970, seventh in 1972, eighth in 1975, and ninth in both 1967 and 1973. This unbroken run of top-ten points finishes over roughly a decade placed him among the most consistent mid-field competitors of the Grand National and early Winston Cup era.
Langley's final full season as a driver was 1975. He continued making occasional starts through 1981 before retiring from driving. As a car owner he then fielded the familiar No. 64 for younger drivers to gain experience, with Tommy Gale, Joe Millikan, Jimmy Hensley, and Ken Schrader among those who drove his equipment. He closed the owner operation after the 1987 season.
On April 15, 1988, Langley was named crew chief for Cale Yarborough and Dale Jarrett, beginning observation duties at the First Union 400.
From April 1989 through November 1996, Langley served as the official pace car driver for every NASCAR Winston Cup event. He became a familiar figure on circuits across the country during this period, and the role was made memorable by the habit of Richard Petty-era champions Dale Earnhardt and Rusty Wallace bumping and drafting his car during caution-period pace laps.
Langley's final competitive race appearance came at the Battle of the NASCAR Legends at Charlotte Motor Speedway in 1991, an exhibition that brought together several veterans of the sport. He beat Cale Yarborough to the line by approximately three feet on the final lap to take the win.
In November 1996, Langley traveled to Suzuka, Japan, to serve as pace car driver for the NASCAR Thunder Special Suzuka exhibition race scheduled for November 24. During a test drive on November 21, he began experiencing chest pains and was taken to Suzuka General Hospital, where he was pronounced dead on arrival from heart failure. NASCAR analyst and former driver Buddy Baker was in the pace car with Langley at the time he suffered the heart attack.
Langley was married to Nancy and had four sons: Elmo Jr., Raymond, William, and Steven. He lived in Harrisburg, North Carolina.
Langley's longevity in NASCAR — as a driver, car owner, crew chief, and official — made him one of the most persistently present figures in the sport across the 1950s through the 1990s. His decade of top-ten points finishes without the resources of a factory-backed team reflects the durability and pragmatism that defined the owner-driver class of his era. His death during an official duty in Japan underscored the international reach NASCAR was beginning to establish in the mid-1990s.