Johannes Hubertus Leonardus de Haas, also known as Jan de Haas was a Dutch animal painter and was mostly interested in cows. He is counted among the first generation of the Hague School.

He grew up in Amsterdam and then moved to Haarlem. In Haarlem he was studying with artist Pieter Frederik van Os, together with Paul Gabriël and Hendrik Dirk Kruseman van Elten. With these two artist he then moved to Oosterbeek were they came in contact with Johannes Warnardus Bilders, a lanscape painter. He later married the daughter of Bilders, Caroline.

In 1855 a few paintings were exhibited in Paris and he received good reviews from Jean Baptiste Gustave Planche who was a noted art critic. Later he moved to Brussels and befriended William Roelofs. His other friend Gabriël also moved to Brussels and de Haas painted cattle in the landscapes for both Roelofs and Gabriël.

De Haas was influential in passing on the style of the school of Barbizon to painters at Oosterbeek. He received multiple golden medals, for his exhibition in Utrecht in 1860 and for his work at the exhibition in Munich in 1869.