Hair loss is characterized by a shortened hair anagen phase and hair follicles (HF) miniaturization. Morroniside is the most abundant iridoid glycoside extracted from Cornus officinalis and has various bioactivities in different cell functions and tissue regeneration. In this study, we investigated the effects and the underlying mechanism of morroniside on hair growth and regulation of HF cycle transition. Morroniside treatment significantly enhanced outer root sheath cell (ORSC) proliferation and migration in vitro. Additionally, morroniside upregulated Wnt10b, β-catenin and lef1. The enhanced ORSC proliferation and migration due to morroniside treatment were partly rescued by a Wnt/β-catenin signaling inhibitor, DKK1. Furthermore, in a hair-induced mouse model, morroniside injection accelerated the onset of anagen and delayed HF catagen, as shown by histological examination. Immunohistochemical analyses revealed that Wnt/β-catenin signaling pathway expression was upregulated in the HFs. These findings suggest that morroniside regulates HF growth and development partly through the Wnt/β-catenin signaling pathway and may be a potential treatment for hair loss.