Janez Jalen was born into a rural family. His father awakened in him a great interest in nature early on in his life. After finishing secondary school in Kranj he studied theology in Ljubljana. His first pastoral appointment was to Srednja vas near Bohinj. The beauty of the surrounding area, which he came to love and admire, was what encouraged him to begin writing. During the First World War he was mobilised into the Austrian Army and served as a curate in the Lebring Army Camp near Graz. After the war he served as a priest in a number of places around Slovenia: Črnomelj, Stara Loka, Trnovo,Notranje Gorice and Ljubljana where he took early retirement in 1933. After the Second World War he re-entered service and was priest in Grahovo and finally Ljubno where he died. He is buried in Rodine.
In his early period Jalen dedicated most of his time to writing plays depicting rural life at the time of the First World War. Among these are Home (Dom, 1923), The Common (Srenja, 1924) and Brothers (Bratje, 1931). Later he began writing prose, in which he also deals with rural life, albeit in a slightly idyllic way. His first novel, Shepherd Marko (Ovčar Marko), was originally published in installments in the magazine Mladika in 1928, the book only being published a year later. In 1958, it was re-published as the first part of Vozarji, an intended quartet about rural life. Jalen died before publishing any further volumes. His most well known work is a tale of a prehistoric people living on the marshes south of Ljubljana, titled Beavers (Bobri) which was published in three parts (Sam, Rod, Vrh; 1942–43). At his death a number of works remained unfinished and unpublished.