Czeslaw Janczarski (September 2, 1911 in the village of Hruszwica, Volhynia Governorate – May 19, 1971 in Warsaw) was a Polish writer of children's books as well as a translator from the Russian language.

In 1932 Janczarski began studies at the Lviv University, two years later he moved to the Warsaw University, where he studied Polish Philology. There, he got in touch with Józef Czechowicz and other poets. Janczarski spent World War II in Lwów, between 1944 and 1946 he lived in Kurów and taught in a school in the area of Lublin, then returned to Warsaw. In the late 1940s, he started working for illustrated magazines for kids, such as Iskierki, Płomyczek and Świerszczyk, also cooperated with the Polish Radio.

Janczarski was the creator of kids' biweekly Mis (1957), and for many years he was editor in chief of the publication. Also, he is the creator of Miś Uszatek, one of the most popular characters among Polish children. Janczarski wrote several books and helped create several animated movies about Uszatek's adventures, they were illustrated by Zbigniew Rychlicki.

He died unexpectedly, during a meeting with children in Siedlce he had a heart attack, and died in a hospital in Warsaw a few days later. Janczarski, author of many books for children was awarded with several orders.