This study aims to determine whether differences exist between the presence of microplastics and mesoplastics in fishes of coral reef and mangrove ecosystems, in Isla Grande, Colombian Caribbean. The collection of three species of coral reef (Centropomus undecimalis, Caranx hippos, and Lutjanus synagris) and three species of mangrove from coral reef (Centropomus undecimalis, Eugerres plumieri, and Archosargus rhomboidalis) were found to have ingested microplastics and mesoplastics, with a significantly higher in the mangrove species than in the coral reef species (1.9 vs. 1.6 items/individual). Furthermore, the average abundance and weight of microplastics and mesoplastics were significantly higher in females than in males (p < 0.05) and the abundance of microplastics and mesoplastics in the intestines was significantly higher than in the stomach (p < 0.05). PE, polyester, PVC, and PET were the most abundant polymers among common plastics found in species of the two habitats. Our findings highlight the importance of more rigorous plastic waste management strategies in areas nearby the coast and mangrove habitats.