Antonius Otto Hermannus (Toon) Tellegen (born 18 November 1941) is a Dutch writer, poet, and physician, known for children's books, especially those featuring anthropomorphised animals, particularly those about an ant and a squirrel.

His writings are also enjoyed by adults, due to the amusing, bizarre situations that Tellegen creates, as well as their dealings with philosophical subjects.

For his lasting contribution as a children's writer, Tellegen was a finalist for the biennial, international Hans Christian Andersen Award in 2006.

His first children's book, written in 1984, was Er ging geen dag voorbij: negenenveertig verhalen over de eekhoorn en de andere dieren (English: Not A Day Went By: forty-nine tales of the squirrel and other animals).

Boxer Books Ltd of London has published in Britain, and distributed in America, several collections of Tellegen's animal stories illustrated by Jessica Ahlberg and translated by Martin Cleaver.