Anderson was born in Croydon, Surrey, the son of a Scottish naval architect. He was educated at Berkhamsted School and attended motor races at Brooklands from a young age, purchasing his first motorcycle — a Douglas — in 1923. He joined the Royal Navy in 1926 before entering his first motorcycle race in 1927 on a Levis borrowed from his sister without her knowledge. He subsequently bought a 500 cc Cotton-Blackburne and took up speedway racing, later earning a Brooklands Gold Star badge for lapping the circuit at over 100 mph on a Grindlay Peerless powered by a J.A.P. engine.
Fluent in four languages, Anderson spent the 1930s competing across Europe on a variety of machinery including Rudge, Velocette, Excelsior, Norton, and DKW. He also wrote briefly for The Motor Cycle magazine. He entered his first major international competition at the 1932 Spanish Grand Prix and rode in his first Isle of Man TT in 1937, finishing 28th in the Senior TT.
Anderson rejoined the Royal Navy during the Second World War and served with the Small Vessels Pool. His name appeared on the Nazi list of prominent British figures to be arrested during the intended invasion of Britain. After the war he returned to racing with great energy, winning 73 races in 1947. That year he claimed the 1947 350 cc European road racing championship — a one-race title at the Swiss Grand Prix — riding his privately funded Velocette KTT Mk VIII.
Anderson signed with Moto Guzzi in 1950. He placed second at the 250 cc Nations Grand Prix at Monza that September, then won his first Grand Prix for the team in the 500 cc class at the 1951 Swiss Grand Prix. At the 1952 Isle of Man TT he set new race and lap records to win the 250 cc Lightweight TT, finishing ahead of teammates Enrico Lorenzetti and Syd Lawton. He ended that season second in the 250 cc World Championship behind Lorenzetti.
In 1953 he retained the Lightweight TT title and successfully lobbied Moto Guzzi management to build a 350 cc machine. With the new bike he won the Belgian, French, and Swiss Grands Prix to claim the 1953 350 cc World Championship, also adding a 500 cc victory at the Spanish Grand Prix. He became the oldest rider in FIM history to win a Grand Prix when he took that Spanish victory at 44 years and 273 days of age. Anderson successfully defended the 350 cc title in 1954 with four Grand Prix victories from nine rounds.
Anderson won the prestigious Mettet Grand Prix invitational on 25 April 1954 and repeated the feat on 1 May 1955. However, he withdrew from the 1955 World Championships after public criticism of the FIM's organisation prompted the federation to cancel his racing licence. He became Moto Guzzi's race team manager but resigned over a dispute about his authority to run the team. He returned to racing with BMW support. On 6 May 1956, at the age of 47, he was thrown from his motorcycle during a race at Floreffe, Belgium, and died from his injuries. He was buried at the cemetery nearest the accident site in Namur.
Fergus Anderson's career spanned more than two decades and bridged the pre-war European racing scene and the early years of the FIM World Championship. His back-to-back 350 cc titles for Moto Guzzi broke the British marque monopoly on that class and helped establish Italian manufacturers as genuine world championship contenders. His age record for the oldest Grand Prix winner stood for many years and reflected an era when experience and tactical intelligence could still outweigh youth.