This study aims to determine the effect of attitudes, subjective norms, and behavioural control (Theory of Planned Behavior/TPB) on the intentions of food seller to use halal products. The final sample consisted of 130 respondents who run the daily business activities of a restaurant in Padang, Indonesia. The systematic random sampling method was used in this research. Multiple linear regression was used to test the hypothesizes. It was found that subjective norm and behavioural control have a positive effect but not significant on sellers' intention to use halal product. However, attitude significantly influence food sellers' intention to use halal product. This study is beneficial to understand the factors that influence halal product usage in the food industry. It could also become a policy-making reference for government and related institution to increase halal food market scale.