Distribution patterns of lit fisheries in the South China Sea (SCS) were investigated using seasonally averaged nighttime light remote sensing data from 2016. Light-fishing activities clearly showed spatial and seasonal patterns and a newly developed “hotspot” with the presence of many intensive lights observed in the open ocean during spring. These satellite observations are consistent with seasonal changes in the fishing grounds of a Chinese large-sized, falling-net fishing fleet based on catch monitoring records for a typical commercial fishing vessel and Vessel Monitoring Systems (VMS) data from this fleet. Catch monitoring records show that this type of vessel operates both on the northern shelf and in the oceanic waters, with apparent seasonal fishing patterns in the SCS. Dominant catches on the shelf include Carangids, Trichiurus japonicus, and Loligo spp., while Sthenoteuthis oualaniensis and Auxis spp. overwhelm catches in the oceanic waters. Furthermore, we compared VMS and Day Night Band (DNB) data to study fishing behaviors of this type of vessel, including match rates between VMS and nightly satellite images and the DNB radiance characteristics of the vessels. This study is valuable for delineating squid fishing grounds in the open SCS and provides an important basis for differentiating light fishing vessels of China from those of other countries, which may be useful for detecting illegal, unreported, and unregulated (IUU) fishing activities. Findings of this study may also shed light on mitigating the emerging threat of light pollution to the local ecosystem of the SCS.