Market monopoly is an economic phenomenon that can have an impact on business competition and public welfare. In Islam, monopoly has certain limitations in accordance with the principles of justice and social welfare. This study aims to analyze Ahmad bin Hanbal's thoughts on market monopoly and examine contemporary cases in Indonesia, namely the 2023 cooking oil monopoly. Using qualitative research methods based on literature studies, this article explores Ahmad bin Hanbal's views on market mechanisms in Islam and how its principles can be applied in the context of a modern economy. The results of the study show that Ahmad bin Hanbal rejects monopolistic practices that are detrimental to society and hinder healthy business competition. A study of the cases of non-subsidized cooking oil in Indonesia shows that the monopolistic practices that occur are contrary to the values of Islamic economic justice. Therefore, stricter regulations and policies oriented towards public welfare are solutions that need to be considered by stakeholders.