Joanna Bartosik (1990) is an author and illustrator of children's books. She created the beloved and award-winning series of books for young children One, Two, Three, and its sequel – Two, Three, Four.

The One, Two, Three series received an honorable mention in the Trzy/Mam/Książki competition organized by the Book Institute in 2015. Two years later, it received an award in the 9th Halina Skrobiszewska Children's Literature Competition and was included on the List of Treasures of the Children's Book Museum.

The entire series was also published by the Czech publisher Meander, and selected books from the series were also published in Brazil.

In 2019, Joanna was invited to the Bologna Children's Book Fair to participate in the panel discussion "TODDLERS: The Very First Books for Absolute Beginners" and to lead art workshops for children. At the same year, she was a speaker at the "The Language of Images in Children's Literature" conference in Lithuania and also led art workshops for children there.

In May 2025, Joanna led art workshops for children at the Salone Internazionale del Libro di Torino. This workshop was based on the Italian edition of the book Three Wishes (Tre desideri), which she illustrated.

In February 2026, in conjunction with the Taiwanese edition of the books My Mum, My Dad and My Grandma, My Grandpa, Joanna spoke about her book illustration technique at the TIBE2026 Taipei International Book Exhibition and led art workshops for children.

To date, the artist has illustrated over 30 children's books, collaborating with companies such as Widnokrąg, WYtwórnia, Natuli, and the Szczecin Philharmonic. Some of the titles she co-published have also been published abroad – in Italy, France, Spain, Canada, Brazil, and Taiwan, as well as in Galician, Korean, Ukrainian, and Czech.

Her illustrations have been presented at exhibitions in Poland, as well as in Bologna, Rome, Frankfurt, and Cyprus.

She regularly creates illustrations for Newsweek Child Psychology and Newsweek Teen Psychology.

Joanna is a lecturer at Collegium Da Vinci in Poznań, where she teaches illustration. She is a member of the illustration collective Ilu Nas Jest. She also loves to dance.