Background: Aflatoxin B1 (AFB1) is a potent hepatocarcinogen commonly found in staple foods from tropical regions. Aim: This scoping review collated existing evidence on AFB1 contamination in rice, maize, and peanut-based products across ASEAN countries to estimate chronic dietary exposure, Margin of Exposure (MOE), and the associated liver cancer risk. Methods: A systematic search was performed in five databases. Estimated Daily Intake (EDI) and risk metrics were calculated using sample-size weighted mean concentrations, along with regional consumption data. Risk characterisation used the benchmark dose lower confidence limit (BMDL₁₀) of 400 ng/kg BW/day, while liver cancer potency levels were adjusted according to Hepatitis B virus (HBV) prevalence for each population. Results: Twenty studies from Malaysia, Thailand, Vietnam, and the Philippines met the inclusion criteria. Peanuts and maize had the highest AFB1 concentrations among all food groups. Peanuts showed the highest contamination in the Philippines, followed by Malaysia, Vietnam, and Thailand. Maize exhibited a similar trend, with the highest levels observed in the Philippines. Most MOE values calculated were below 10,000, indicating a major public health concern. An exception was peanuts in Thailand, where MOE values exceeded 10,000, thus indicating a lower genotoxic carcinogenicity risk. The estimated liver cancer burden due to dietary AFB1 varied widely among countries and commodities. Conclusions: These findings show significant differences in AFB1 exposure in the ASEAN region. There is a need for improved surveillance, better post-harvest management, and harmonised regional risk management strategies.