Joseph Leopold Ratinckx was a Belgian painter.

His father wanted him to train as a typographer after elementary school and therefore refused his son's request to attend courses at the Academy of Fine Arts. As a result, Jos ended up as an apprentice printer in the studio of the Ratinckx brothers, his father's cousins. However, it was his employer who persuaded his father to give his son the opportunity to become a lithographer. For nine years, he took drawing and painting lessons under the guidance of renowned professors and artists, including Nicaise De Keyser and Karel Verlat.

He became skilled in the art of lithography, but this profession no longer appealed to him. He wanted to be able to express himself fully as a painter. Although he was known as a skilled watercolourist, his preference was for oil painting. He was elected to the municipal council on 17 November 1895, but left the council when he was appointed director and teacher at the municipal art school.