Behavioural science is the study of human behaviour to understand the motivations and causal relationship between different actions, usually by means of experiments. It is a powerful tool for policy makers to formulate policies to shape public behaviours, from eco-living, to on-time tax payment. It can also be used in social entrepreneurship as a tool to change public attitude towards certain social issues and shape their behavior towards desirable outcomes, such as supporting the employment of marginalized people like the disabled and ex-criminals; environmental protection; wearing masks during Covid-19. Despite its promise, there is little understanding of how it can be used to reform our society. In this forum, we will bring in relevant experts to share their experience on using behavioral science to develop better policies, better social enterprises, and a better society.