Peatlands are sources of the bioaccumulating neurotoxin methylmercury (MeHg). Despite recent pollution controls (ca.1970s), historical atmospheric deposition from industrial smelters in Sudbury, Ontario, Canada has left a legacy of mercury (Hg) contamination. The return of Sphagnum moss, a key driver of ecohydrological and biogeochemical peatland functions, may alter Hg cycling but the effects of peatland recovery on MeHg dynamics and mobilization in this landscape remain poorly understood. To assess how recovery from contamination impacts Hg cycling, we used an established peatland contamination/recovery gradient (no recovery (NR); moderate recovery (MR); and minimal-contamination, full recovery (FR)). NR had the highest mean total mercury (THg, 13.4 ng/L) and MeHg (0.5 ng/L) but lowest percent MeHg (%MeHg, 2.3%), while FR and MR had higher %MeHg (4.8% and 4.5%, respectively). Interannual patterns (2024 vs. 2023) revealed increased THg and MeHg but reduced %MeHg at NR in 2024, while both MR and FR showed lower THg and higher MeHg and %MeHg likely due to greater precipitation and higher water tables in 2024. Across all peatlands, MeHg concentrations were positively correlated with indicators of low molecular weight DOM and total sulfur. At FR and MR, Hg concentrations generally increased with higher water tables, whereas at NR lower water tables were associated with increased Hg due to increased exposure to the contaminated peat layers. We demonstrate that recovery status, hydrology, and legacy pollution interact to regulate Hg cycling in smelter impacted peatlands, and that return of Hg cycling maybe a useful indicator of peatland function.