The study provides data on the feeding habits and intensity of Glossogobius sparsipapillus, a potential candidate for aquaculture, by analyzing the relative gut length (RGL) and gastro-somatic (GaSI) indexes. Samples of 661 G. sparsipapillus individuals (331 males and 330 females) were collected using gill nets in estuarine regions, ranging from Hoa Binh to Dong Hai and Dam Doi, in the Mekong Delta from December 2019 to November 2020. The analyzed results show that the G. sparsipapillus’ RGL changes with the fish size, gender, season, month and site variables, indicating that the goby’s feeding habit displays sexual, intraspecific and spatio-temporal variations. Males and females at different fish sizes, seasons, months, and sites fall into the carnivorous category, since RGLs are significantly lower than the threshold of 1. Like the RGL, the G. sparsipapillus’ GaSI varies between genders, fish sizes, seasons, months and sites, suggesting intraspecific and spatio-temporal variations in both males’ and females’ feeding intensity. The G. sparsipapillus’ feeding habit is not regulated by the interactions fish size × site, fish size × season and site × season. The feeding intensity of this species is influenced by the fish size × site and fish size × season combinations of factors, but not to by the site × season combination. This contribution to the knowledge on G. sparsipapillus’ feeding habit and intensity supports a better understanding of the species’ adaption and aquaculture in the study region.