Pigeons are widespread worldwide, including remote islands. These relatively large-bodied birds can significantly influence the ecosystem structure and function through their feeding habits, especially on islands where large mammals and a few avian taxa are scarce or absent. However, their dietary guilds, such as frugivores and granivores, and their ecological roles as seed dispersers and predators are poorly understood. This study presents a comprehensive bibliographic review of the relationships between pigeons and the fruits and seeds they consume globally, analysing 369 scientific publications to explore research trends and gaps. We categorised pigeon dietary data based on the consumption of fleshy fruits or seeds and dry fruits, along with functional data represented by seed dispersal and predation. This approach also allowed us to explore how different habitat types (islands and continents) influence pigeon feeding patterns. Although our review covered dietary and seed dispersal/predation functional data for 23 and 35 genera on islands and 23 and 28 genera on continents, data at the species level remain insufficient, even in bioregions with high pigeon species richness. Poaceae (114 spp.), Moraceae (114 spp.), which includes 94 Ficus species, and Fabaceae (98 spp.) were the most represented families among the recorded dietary plants of pigeons. It was predicted that the proportion of fleshy fruit in the pigeon diet would be significantly higher on islands than on continents, with observed values of 0.66 and 0.58, respectively. While some pigeon genera are obligate frugivores, others have a diet that falls between frugivory and granivory. The comparison between seed dispersal and seed predation indicated that seed predation was underestimated in diet studies. However, functional data on the seed dispersal and predation showed that several genera could be both seed dispersers and predators. In conclusion, this review revealed a continuous trend of frugivore-granivore guild and seed disperser-predator functions in pigeon taxa. This suggests that the interactions between pigeons and fruits may be more complex than the commonly understood dichotomous categories. We also identified under-researched dietary data and publication biases across bioregions and topics, suggesting avenues for further investigation.