Jan Harm Weijns (Zwolle, 6 December 1864 – Rotterdam, 14 December 1945) was a Dutch painter, draftsman and a teacher at the academy. He is mentioned in the press and literature as J.H. Weijns and J.H. Weyns.

Weijns was a son of shearer Arie Nicolaas Weijns and Alida Maria Weijns. He was taught at the city drawing school in Zwolle by Jan Derk Huibers. He continued his education at the Rijksnormaalschool voor Teekenonderwijzers in Amsterdam (1881-1885), with his teacher Willem Molkenboer, where he obtained the MO drawing certificate.

He returned to Zwolle for a short time and became a drawing teacher in Enschede in 1886. In 1892 he was appointed the role of teacher at the HBS on the Kortenaerstraat in Rotterdam, from 1895 he was also a teacher at the Academy of Fine Arts and Technical Sciences.

His pupils included Otto van Bennekom, Jan Havermans, Wam Heskes, Dirk Homberg and Otto Verhagen. Weijns painted and drew landscapes, portraits, interiors and still lifes.

He was affiliated with Arti et Amicitiae, Sint Lucas, the Pulchri Studio and the Rotterdamsche Kunstenaars-Sociëteit.

He exhibited several times and won silver medals for his work in Amsterdam (1912) and San Francisco (1916). From 1915 onwards Weijns exhibited with ‘De Rotterdamsche Tien’, a club of artists that also consisted of Christiaan Johannes Addicks, Gerard Altmann, J.G. Heijberg, Sara Heijberg-Ledeboer, Huib Luns, Ferdinand Oldewelt, Adriaan de la Rivière, Martin Schildt and August Willem van Voorden.

He was appointed Knight in the Order of Orange-Nassau in 1925. He died in 1945, at the age of 81.