Phthalates are chemicals found in many everyday consumer products (food packaging, toys, vinyl flooring, cosmetics, household cleaning products, paints, etc.). Diet is estimated to account for 90% of total exposure. The use of certain phthalates in toys, electronic devices, food packaging, medical devices, and cosmetics is regulated by European and French legislation. Phthalates are considered endocrine disruptors, and most are classified as "substances toxic to reproduction." Effects are suspected on the male reproductive system and thyroid function. Prenatal exposure could disrupt the development of certain tissues or organs, with potential health consequences in adulthood or even several generations later, through epigenetic mechanisms. As part of the national biomonitoring program, the Esteban cross-sectional study made it possible for the first time to measure exposure levels to 9 phthalates (DEP, DnBP, DiBP, BBzP, DMP, DCHP, DEHP, DiNP, DnOP) in the mainland French population and to investigate their determinants. Urinary concentrations of phthalate metabolites were measured in a subsample of 500 children and 897 adults aged 6 to 74 years, enrolled in the study between April 2014 and March 2016. Most metabolites were quantified in 80–99% of adult and child samples, except for MiNP (<20%), MCHP, and MnOP (<1%). The highest concentrations were measured for MEP (51.2 and 71.4 µg/g of creatinine in children and adults, respectively), MiBP (47.1 and 38.8 µg/g of creatinine, respectively), and the sum of DEHP metabolites (27.7 and 22.2 µg/g of creatinine, respectively). Children had the highest exposure levels, except for MEP, a marker of cosmetic and hygiene product use. The results obtained were consistent and similar to those observed in North American countries (United States, Canada). The investigation of exposure determinants showed an increase in DnOP and DEHP metabolite concentrations in children associated with the use of cosmetics and hair care products. In adults, exposure to short-chain phthalates (MnBP, MiBP, MBzP, MEP) was increased by the presence of vinyl flooring in the home and by being a smoker or former smoker. Despite restrictions on the use of certain phthalates, the results of the Esteban study show that the entire population was exposed to at least one phthalate at a quantifiable urinary concentration level. Since the half-life of these compounds is short, this finding demonstrates that phthalates continue to be ubiquitous in the environment and in everyday consumer products.