The objective of this study was to describe and quantify the influence of the socioeconomic environment on cancer incidence for each of the 15 most common solid tumors and the three most common hematologic malignancies in France. The analysis was based on data from French cancer registries that are members of the Francim network (French Network of Cancer Registries). The European Deprivation Index (EDI) was used to assess the socioeconomic environment. A statistically significant incidence gradient increasing with socioeconomic deprivation was observed for cancers of the stomach, liver, lip, mouth, and pharynx cancers, and lung cancer in both sexes; for laryngeal, esophageal, pancreatic, and bladder cancers in men; and for cervical cancer in women. Conversely, a statistically significant incidence gradient increasing with socioeconomic advantage was observed for melanoma in both sexes, for prostate and testicular cancers in men, and for ovarian and breast cancers in women. The proportion of cancer cases attributable to social disadvantage was highest for laryngeal cancer (30.1%), lip, mouth, and pharynx cancers (26.6%), and lung cancer (19.9%) in men, and for lip, mouth, and pharynx cancers (22.7%) and cervical cancer (21.1%) in women. Nearly 15,000 cases of cancer could be prevented in France each year by improving living conditions and promoting the health of the most disadvantaged populations.