The Reformed tradition, emerging in the 16th-century Reformation, consists of a variety of sources that often lead to complex and differing views about beliefs, doctrines and ethics. However, this tradition and theology have always stressed the significance of social justice and diakonia as important aspects of faith and ministry, even though its great sense of diversity has often nuanced and stressed different levels of understanding and engagement of social justice. This article aims to show that social justice and diakonia are (...) integral to Reformed tradition and practice. Using mainly the methodologies of literature review and contextuality (the author’s context), this article establishes that social justice is grounded in the history, theology, spirituality, confessions and polity of the Reformed faith. The latter aspects are also contained in the notion that to be Reformed is to be ecumenical. In this sense, Reformed tradition is concerned about the whole world and all creation. Contribution: The diverse and complex nature of Reformed tradition and theology often creates a sense of confusion on how Reformed Christians understand social justice and diakonia. This article offers a significant contribution to establishing that social justice is an integral aspect of Reformed tradition. By firmly grounding social justice in the history, theology, spirituality, confessions and polity of the Reformed faith, the author makes a significant contribution to a debate that has pervaded Reformed churches over many centuries. (shrink)