Because arsenic occurs naturally in the environment and has numerous industrial and agricultural applications, it is widely present in our environment. Furthermore, the International Agency for Research on Cancer (IARC) has classified arsenic and its compounds as Group 1 carcinogens for humans. It also has numerous non-carcinogenic effects. In France, the National Nutrition and Health Survey (ENNS) estimated exposure levels to total arsenic, inorganic arsenic, and its two metabolites in the general adult population in 2006–2007. However, no study to date had measured these compounds in the pediatric population, except in certain local situations involving contaminated sites and soils. Since then, the Esteban cross-sectional study (Study of Health, Environment, Biomonitoring, Physical Activity, and Nutrition) has measured exposure levels to total arsenic (As T) and inorganic arsenic and its two metabolites (Asi + MMA + DMA) in the mainland French population aged 6 to 74 years between April 2014 and March 2016. Quantification rates were 100% for both children and adults. The geometric means were, respectively, 27.7 and 8.2 µg/g of creatinine for As T and 17.7 and 5.4 µg/g of creatinine for Asi + MMA + DMA in adults, and 17.7 and 5.4 µg/g of creatinine for As T and 17.7 and 5.4 µg/g of creatinine for Asi + MMA + DMA in children. The investigation of exposure determinants confirmed the exposure factors known from the literature: consumption of fish and consumption of crustaceans and mollusks. The levels measured in adults were similar for As T but higher for Asi + MMA + DMA than those measured in the ENNS study in 2006–2007. The higher As T levels in the French adult population compared to North American countries had also already been highlighted in the ENNS study. However, the levels found are lower than those measured in Asia. This discrepancy—and the fact that it narrows when measuring Asi + MMA + DMA—could be explained by higher consumption of seafood (a known source of arsenic exposure) in France compared to North American or Northern European countries. Given the health effects of arsenic and its compounds, it would be desirable to reduce exposure. The exposure reference values derived from this study could help support a public health strategy.