Theodora Beckmann (née Petie; 23 July 1923 – 5 May 2004), better known by her pen name Thea Beckman, was a Dutch author of children's books.

In wake of the 1929 economic crisis, her father lost his job and Beckman was glad she had managed to finish her studies, especially after World War II occurred.

Her publisher urged her to change it to Beckman with only one "n", to avoid her name from appearing "too German", in wake of Germany's negative reputation after World War II.

Beckman is best known for Crusade in Jeans,[1][2] a 1973 children's time travel novel for which she was awarded the Gouden Griffel.

In 2005, it was given to Belgian authors Jean-Claude van Rijckeghem and Pat Beirs for the novel Jonkvrouw.