Supplier and vendor selection is considered as a significant challenge for supply chain long-term performance. The careful selection and assessment of suppliers is a critical first step in ensuring the company's stability. Selecting and evaluating suppliers is a multi-faceted and difficult task. Supplier selection and assessment are often based on data. This information, particularly in non-economic, societal, and ecological dimensions, is not easily accessible, certifiable, or audited. Considering the potential behind blockchain technology, this study has proposed a methodology for the integration of blockchain technology in the supplier selection process. Conducting a comprehensive literature review, the study has considered the existing traditional or existing supplier selection process. Using blockchain technology features, especially smart contracts, a new theoretical methodology is proposed. The methodology applies blockchain to tackle the existing problems in the supplier selection process, like the errors in data collection, authenticity of the data collected, means of collecting data, data storage and access. The proposed methodology includes the selection of criteria and analysing the supplier’s performance based on the criteria. The blockchain-enabled platform ensures the integration of data from suppliers, which benefits from a decentralised planning system. The smart contract ensures the establishment of supply contracts. The study has discussed the practical aspects of the implementation of the methodology.