Hemiphlebiidae are the most basal lestomorphan family following the latest phylogenetic analysis of the Zygoptera: this unique damselfly family today contains one relict species found in the wetlands of Australia. It was, however, very diverse and widespread during the Mesozoic. Nevertheless, very few species were known obscuring the origination and early evolution of the family. Here we propose a new stem hemiphlebioid taxon (Protohemiphlebiidae Zheng, Jarzembowski & Nel, fam. nov.) based on a new genus and two species: Protohemiphlebia zhangi Zheng, Jarzembowski & Nel, sp. nov. and Protohemiphlebia meiyingae Zheng, Jarzembowski & Nel, sp. nov. The new family shares the characters of both Hemiphlebiidae and Coenagrionoidea, but it is more closely related to Hemiphlebiidae in having the pterostigma with a ‘star-shaped’ microsculpture, and AA originating from the wing base slightly distal of Ax0. Protohemiphlebia Zheng, Jarzembowski & Nel, gen. nov. is further considered to belong to the stem group of Hemiphlebioidea, instead of belonging to the Hemiphlebiidae, in possessing pretibial combs and a weakly kinked RP1 below the Pt-brace. The new damselflies will help to calibrate the origin of Hemiphlebiidae, which could be earlier than their current oldest records in the Kimmeridgean (Late Jurassic).