In the last two decades, South Africa has experienced a series of xe- nophobic attacks directed at black Africans foreigners from different parts of Africa. Lack of a deeper sense of diversity and plurality has led to low levels of social trust, social cohesion and even social peace. Factors such as poverty, population increase, violent conflict, civil wars and environmental stress have led to tremendous migrations in Africa. Immigration has contributed to xenophobic violence in South Africa. This paper examines the contribution that Thomas Aquinas’s theory of natural law can make to the phenomena of xenophobia. Aquinas’s na- tural law through its underlying principles of human value and freedom can be used to challenge issues surrounding social injustice, in particular xenophobic violence in South Africa. For Aquinas, leading a morally justified and self-fulfilling life requires not only following the precepts of the natural law which dictates doing right actions, but also in having a good or virtuous disposition.