The genus Zanthoxylum (Rutaceae) has a rich fossil record ranging from the Eocene to the Pleistocene across various regions worldwide. However, its earliest occurrence in South China has not been confirmed through direct fossil evidence until now. Four fossil species of Zanthoxylum from South China are described, including a new species, Zanthoxylum guipingense Xu, Song et Jin, based on well-preserved seeds from the Miocene Erzitang Formation of Guiping Basin, Guangxi; a fossil species, Zanthoxylum trachyspermum, from the Oligocene Yongning Formation of Nanning Basin, Guangxi; an extant species, Zanthoxylum nitidum, and another fossil species, Zanthoxylum sp., from the Upper Pleistocene of the Maoming Basin, Guangdong. Fossil evidence suggests that these East Asian fossil species likely dispersed from Europe via the Tethys margin. This study confirms that South China has likely served as a climatically suitable area for Zanthoxylum since at least the Oligocene. From the Oligocene to the Pleistocene, this genus remained highly diverse in this region, highlighting the region's longterm ecological stability and biogeographic importance.