Foglar was born and grew up in Prague, capital of Bohemia. Because his father died prematurely he was brought up in rather poor material conditions by his mother. He was strongly influenced by romantic parts of Prague. All of the fictional towns in his novels are more or less derived from Prague. During the 1920s, Foglar was strongly influenced by German independent Wandervogel movement as well as Scout movement led by Antonín Benjamin Svojsík under Czech name Junák.

During 1930s and 1940s, Foglar worked as a magazine editor in one of the largest Prague publishing houses, Melantrich. He edited several journals for youths:
Mladý hlasatel ("Young herald"), 1938–1941
Junák ("Scout"), 1945–1949
Vpřed ("Ahead"), 1946–1948

and he wrote articles for even more journals including the Skaut, Sluníčko, ABC, and the Tramp.

After Communist coup in 1948 Foglar was kicked out of publishing house, his magazines were liquidated and his books prohibited, as was the Scout movement and independent youth clubs. For many years he worked as tutor in youth internate schools and homes. During the fall of censorship at the end of 1960s, he published some new books and the re-editions of the olders. After Soviet occupation of Czechoslovakia his books were newly banned until 1989.

Foglar lived with his mother caring for her until her death in high age and never married.

One of the key motives of Foglar's novels is the tension between the loneliness and close friendship between young male heroes. These are especially distinctive in novels 'Přístav volá', 'Kdyz duben přichází', 'Chata v Jezerní kotlině', 'Modra rokle' and 'Tajemna Rasnovka'. These novels are also non-scout ones, picturing independent life of youths. On the other hand, in second large group of his novels, a 'group hero' novels, the plot is based on stories of some organized group of youths, with less individual psychology and more action and adventures. The heroes are boy scouts or independent clubbists.