This paper aims to argue that Father Franco Mella, an Italian Catholic missionary in Hong Kong, is a forerunner of Hong Kong Christians who strive for a just society. First, Mella’s thoughts on liberation theology, rooted in the teachings of Vatican II and the thoughts of Lorenzo Milani and Maoism, are introduced. Second, how his practice serves as a living example of Mao’s struggle ethic and a preferential option for the poor is illustrated. Through the praxis of hunger strike, he transforms the violent ethics of revolution into a form of nonviolent resistance. To conclude, his fight against injustice is an exemplar of liberation theology for Hong Kong Christians in responding to injustice in the post-Umbrella Movement era.