Theodora Beckmann, better known by her pen name Thea Beckman, was a Dutch author of children's books.

Crusade in Jeans (1973) is a children's novel written by Thea Beckman. It contains a fictional account of the Children's Crusade of 1212, as witnessed by Rudolf Hefting, a boy from the 20th century. The original Dutch title is Kruistocht in spijkerbroek. A film version was released in 2006.