A fish-eating enantiornithine bird with a gastric pellet composed of fish bones has recently been reported from the Lower Cretaceous Jiufotang Formation of Liaoning Province, northeastern China. Along with other discoveries, this specimen reveals that distinct features of modern avian digestive system were well established in those early birds. On the basis of a detailed anatomical study presented here, we show that this fish-eating enantiornithine bird represents a new taxon, Piscivorenantiornis inusitatus, gen. et sp. nov. The well-preserved elements of the skull, neck, sternum, and pelvis further enrich our understanding of the morphological diversity in early enantiornithines. Most notably, the cranial articular facet of the caudal cervical vertebra is dorsoventrally concave and mediolaterally convex, a feature otherwise unknown among other birds and with unclear functional significance.