Johnny Thomson was born in Inverness, Alabama, USA (not Scotland). Despite this he was still known as "the Flying Scot". He started in Midgets before World War II.
He drove in his first feature race at the Seekonk Speedway in 1947.
A versatile racer, Thomson moved up to Championship and Sprint Cars in the Bay State Racing Association, the United Car Owners Association, ARDC and AAA. He won the New England Championship in 1948, with 32 wins, then repeated as champion in 1949.
He drove a 1940 Ford in stock car races in the Jacksonville, Florida, area in 1950, winning 16 races and in 1951 and 1952 he raced an Oldsmobile in a few NASCAR races without any success. In 1952 however he had more luck in open wheelers, winning the AAA Eastern Midget Championship.
He first raced in the Indy 500 in 1953. After qualifying in 33rd spot he went out after just six laps. Back the following year he qualified his Nichels/Offy impressively putting the car in fourth spot on the grid. Unfortunately he race ended early again after 165 laps. Away from Indy he had better luck capturing the 1954 Eastern Sprint Car Championship that year.
At the 1955 Indianapolis 500 Thompson started 33rd and last and came through to finish fourth. Three more dissapointing results followed at the 'Brickyard' though once again he did well elsewhere finishing runner up in the Eastern Sprint Car Championship in 1956 and 1957 before taking the title again in 1958.
He put in his best performance at Indy in 1959 when he set a record speed of 145.900 to take pole for the 500. He finished the race in third.
He backed that up with fifth in 1960. Sadly he lost his life in a crash at Allentown Fairgrounds later that year.
In all he won seven Indy Car races and finished third in the AAA points race on three occasions; 1955, 1958 and 1959.