Sediment geochemistry and 165 detrital zircon grains U–Pb ages are analyzed from the Ventosa beach sediments in the Gulf of Tehuantepec, Mexican Pacific. The objective is to investigate the sediment weathering condition, compositional variations, and to locate the source areas delivering sediments to the coast. Weathering indices reveal a moderate chemical weathering, indicating that the sediments are chemically immature. The SiO2 content (~72–78 wt. %) and the trace element concentrations indicate that the beach sediments are dominantly derived from the felsic igneous rocks. The rare earth element (REE) patterns of the Ventosa sediments are homogeneous and are depleted relative to the average upper continental crust (UCC) values. The environmental indices reveal a “moderately severe enrichment” for Cu content (Enrichment Factor EF = 5.62–8.87; and Geo Accumulation Index I_geo = 1.41–1.98). Anthropogenic enrichment in Pb, Ba, and Zn contents with the possibility of adverse aquatic biota effect is also observed. Th/U ratios in zircon grains are >0.3, indicate an igneous origin. Two major U–Pb age groups are identified i.e. (1) Miocene (~23–12.9 Ma) and (2) Proterozoic (Neoproterozoic: ~999–545 Ma; Mesoproterozoic: ~2549–1006 Ma). These ages suggest that the zircon grains were originated from the nearby source terranes, most likely from the Cenozoic plutons exposed along the southern Oaxaca coastal region, as well as the volcanic and sedimentary rocks of the Todos Santos Formation.