As part of the national biomonitoring program, the Esteban cross-sectional study conducted in 2014–2016 measured exposure levels to organophosphate pesticides in the French mainland population, specifically for the first time among children aged 6 to 17, and for the second time among adults aged 18 to 74. Urinary concentrations of specific organophosphates were measured in a subsample of 245 children and 754 adults, while concentrations of non-specific organophosphates were measured in a subsample of 500 children and 899 adults. The specific organophosphate pesticides measured in the general population as part of the Esteban study were either barely quantifiable (<4%) (chlorpyrifos, chlorpyrifos-oxon, chlorpyrifos-methyl, 3,5,6-trichloro-2-pyridinol [TCPy], 4-nitrophenol), or 100% non-quantifiable (chlorpyrifos methyl-oxon, parathion, parathion methyl). The dialkyl phosphate metabolites (DEP, DETP, DEDTP, DMP, and DMDTP) were each measured at quantifiable concentration levels in less than half of the sample, with the exception of DMTP, which was quantified in 92.6% of children and 82.5% of adults, respectively. DMDTP and DEDTP were quantified very rarely in both children and adults (<3%). The mean urinary concentration (geometric mean) of DMTP was 4.01 µg/L (4.06 µg/g creatinine) in children and 2.78 µg/L (2.002 µg/g creatinine) in adults. The results of the Esteban study show that the exposure reference values (ERVs) for dialkyl phosphate metabolites are higher in children compared to adults, with the exception of DEP, which has an ERV in children that is half that of adults. The distributions of dialkyl phosphate metabolite concentrations in adults in the Esteban study are generally lower or similar to those observed in the ENNS study. Comparison of exposure levels with international studies remains limited, given the low quantification rates of dialkyl phosphates in the Esteban study and methodological differences between studies or differences in how results are reported. Analysis of exposure determinants did not identify sources of exposure to organophosphorus pesticides in children. However, younger children had higher DMTP concentrations than older children. Among adults, reporting that they did not consume, or consumed less than once a month, organically produced foods (dairy products, eggs, poultry and other meats, fruits and vegetables, whole grains, or whole-grain bread) was associated with an increase in the average urinary concentration of DMTP. The sharp decline in dialkyl phosphate metabolite levels in the French population over the past ten years may result from the decline in the use of organophosphate pesticides in France, which have been replaced by pyrethroids. However, sources of environmental and dietary exposure to organophosphates appear to persist in the general population in France. It is important to continue monitoring trends in this exposure over time in the population for substances still detected to date.