James Charles Bigglesworth, nicknamed "Biggles", is a fictional pilot and adventurer, the title character and hero of the Biggles series of adventure books, written for young readers by W. E. Johns (1893–1968). Biggles made his first appearance in the story "The White Fokker", published in the first issue of Popular Flying magazine and again as part of the first collection of Biggles stories, The Camels Are Coming (both 1932). Johns continued to write "Biggles books" until his death in 1968. The series eventually included nearly a hundred volumes – novels as well as short story collections – most of the latter with a common setting and time.

The chronology of the canon, spanning both world wars, set up certain inconsistencies over the unavoidable ageing of Biggles and his friends. Also later editions had to be somewhat edited in line with changing norms of acceptability, especially regarding race, and in view of the pre-teenage readership who increasingly favoured both the books and the comics.

Biggles first appears as a teenaged "scout" (fighter) pilot in the Royal Flying Corps (RFC) during the First World War. He joined the RFC in 1916 at the age of 17, having conveniently "lost" his birth certificate. Biggles represents a particularly British hero, combining professionalism with a gentlemanly air. Under the stress of combat he develops from a slightly hysterical youth prone to practical jokes to a calm, confident, competent leader. He is occasionally given "special" (secret) missions by the shadowy figure of Colonel (initially Major) Raymond (Air Commodore in later books, reflecting the creation of the Royal Air Force with its own ranks), who is already involved with the intelligence side of operations. Biggles is accompanied by his cousin Algernon ('Algy') Lacey and his mechanic Flight Sergeant Smyth, who accompany Biggles on his adventures after the war. Added to the team in 1935 is the teenager Ginger Hebblethwaite.

W. E. Johns was himself a First World War pilot, although his own career did not parallel that of Biggles particularly closely. The author's initial war service was as an infantryman, fighting at Gallipoli and on the Macedonian front. He was commissioned as a second lieutenant in September 1917, seconded to the Royal Flying Corps and posted back to England for flight training: Johns served as a flying instructor in England until August 1918, when he transferred to the Western Front. On 16 September 1918, his De Havilland DH4 was shot down on a bombing raid. His observer, Lieutenant Amey, was killed (in two of the stories in Biggles Learns to Fly, observers flying with Biggles are killed or badly wounded), but Johns survived to be taken prisoner of war. Johns remained with the RAF until 1927, latterly as an administrative officer rather than a pilot: his final rank was Flying Officer (equivalent to Lieutenant in the RFC) rather than the "Capt." that formed part of his pen name.

While the purpose of the Biggles stories was to entertain adolescent boys, in the First World War books Johns paid attention to historical detail and helped recreate the primitive days of early air combat, in which pilots often died the first time they were in action and before devices such as oxygen supply and parachutes for those on board had become practical. Various models on which the Biggles character might have been based have been suggested, including rugby player and WWI flying ace Cyril Lowe, fighter pilot Albert Ball, and air commodore Arthur Bigsworth. Johns stated that the character was a composite of many individuals in the RFC (including himself).

The bulk of the Biggles stories are set after the First World War, and after Johns' flying career was over. Biggles has an unusually lengthy career, flying a number of aircraft representative of the history of British military aviation, from Sopwith Camels during the First World War, Hawker Hurricanes and Supermarine Spitfires in the Second World War, right up to the Hawker Hunter jet fighter in the postwar adventure Biggles in the Terai. In these later books geographic and historical accuracy is less evident and the grim detail of the first stories is moderated for an increasingly younger readership. The books were successful and were translated into Czech, Danish, Dutch, Finnish, Flemish, German, Hungarian, Icelandic, Italian, Norwegian, Portuguese, Spanish and Swedish.

According to stories in The Boy Biggles and Biggles Goes to School, James Bigglesworth was born in India in May 1899, the son of an administrator in the Indian Civil Service and his wife. James was the younger of two sons, Charles being the elder by five years. The young James had little contact with European culture and commenced a lifelong affection for India, befriending the local Indian boys, exploring the countryside and learning to speak fluent Hindi. He retained a lifetime gift for languages and as an adult spoke French and German fluently, with a "fair command" of other languages. He spent holidays in England, under the custody of "Dickpa", an eccentric uncle and inventor who lived in rural Buckinghamshire. When Biggles, now an adult, visits Dickpa, his father's brother, again, an adventure begins that takes both men to Brazil (the Cruise of the Condor). Biggles then attended Malton Hall School in Hertbury, England. His first encounter with an aircraft was with a Blériot that landed on the school cricket ground.

Biggles left school and initially joined the army as a subaltern in the Royal Flying Corps and learned to fly in the summer of 1916, at No. 17 Flying Training School, which was at Settling, Norfolk, flying solo after two hours of instruction. He then attended No. 4 'School of Fighting' in Frensham, Lincolnshire.