The presence of excessive arsenic (As) in paddy fields poses a significant risk to human health due to its accumulation in rice grains. However, the current level of As in Sri Lankan paddy fields remains unclear. Therefore, this research aims to assess the distribution of exchangeable As concentration and investigate the effects of agro-climatic zones (ACZs), soil orders, and water sources on exchangeable As concentration in Sri Lankan paddy fields. For this purpose, 7,154 soil samples were collected from paddy fields using a stratified random sampling method representing six ACZs, six soil orders, and three water sources. Arsenic extraction was made using 0.01 M CaCl2 followed by the detection with Inductive Coupled Plasma Mass-Spectrophotometry. The concentration of exchangeable As ranged from 0.01 to 392.9 µg/kg with an average of 24.6 µg/kg. Samples from the Low-country Wet zone exhibited higher exchangeable As levels compared to those from the Low country Dry zone (p<0.05). Among soil orders, Histosols, Inceptisols, and Ultisols showed higher exchangeable As concentrations than Alfisols and Vertisols (p<0.05). Rainfed paddy fields had higher exchangeable As compared to the fields with access to supplementary irrigation. Additionally, exchangeable As concentration was inversely correlated with soil pH and paddy grain yield (p<0.05). The observed variations in soil-As concentration across ACZs, soil orders, and water sources highlight the need for climate, soil order, and water source-specific strategies to mitigate further accumulation of As in paddy fields.