Mercury (Hg) isotopic compositions in hair and dietary sources from Wanshan (WS) Hg mining area, Guiyang (GY) urban area, and Changshun (CS) rural area were determined to identify the major Hg exposure sources of local residents. Rice and vegetables displayed low δ202Hg and small negative to zero Δ¹⁹⁹Hg, and are isotopically distinguishable from fish which showed relatively higher δ²⁰²Hg and positive Δ¹⁹⁹Hg. Distinct isotopic signatures were also observed for human hair from the three areas. Shifts of 2 to 3‰ in δ²⁰²Hg between hair and dietary sources confirmed mass dependent fractionation of Hg isotopes occurs during metabolic processes. Near zero Δ¹⁹⁹Hg of hair from WS and CS suggested rice is the major exposure source. Positive Δ¹⁹⁹Hg of hair from GY was likely caused by consumption of fish. A binary mixing model based on Δ¹⁹⁹Hg showed that rice and fish consumption accounted for 59% and 41% of dietary Hg source for GY residents, respectively, whereas rice is the major source for WS and CS residents. A compound-specific stable isotope analysis (CSIA) of MeHg was performed on rice samples collected in the Wanshan mercury mining area. Distinct Hg isotope signatures were observed between IHg and MeHg in rice samples (in mean±standard deviation: δ²⁰²HgIHg at −2.30‰±0.49‰, Δ¹⁹⁹HgIHg at −0.08‰±0.04‰, n=7; δ²⁰²HgMeHg at −0.80‰±0.25‰, Δ¹⁹⁹HgMeHg at 0.08‰±0.04‰, n=7). Using a binary mixing model, it is estimated that atmospheric Hg contributed 31%±16% of IHg and 17%±11% of THg in the rice samples and the IHg in soil caused by past mining activities contributed to the remaining Hg. This study demonstrated that Hg stable isotopes are good tracers of human exposure and Hg pollution in rice.