Keller participated in the NASCAR "Strictly Stock"/"Grand National" (predecessors to the current Sprint Cup) series from 1949 to 1956 with 29 career starts. He won two races during the 1954 season and was the first driver in the history of NASCAR's top division to have won a race in a foreign-built car, winning the 1954 Grand National road-race at the Linden Airport in New Jersey, driving a Jaguar owned by big band leader Paul Whiteman.
In 1954 Keller began a transition to Champ Cars. He drove in the AAA and USACChampionship Car series, racing in the 1954-1959 and 1961 seasons with 32 starts, including the Indianapolis 500 races in all but the first of those years. He was involved in the crash that killed Bill Vukovich in 1955. He finished in the top ten 13 times, with his best finish in 2nd position, in 1956 at Atlanta and in 1961 at Milwaukee. His best Indy finish was 5th in 1961.
Keller died as a result of injuries sustained in a fiery Champ Car crash at the Arizona State Fairgrounds track.
The Indianapolis 500 was part of the FIA World Championship from 1950 through 1960. Drivers competing at Indy during those years were credited with World Championship points and participation. Al Keller participated in 5 World Championship races but scored no World Championship points.