Leonardo Boff, born as Genézio Darci Boff, is a Brazilian theologian, philosopher writer, and former Catholic priest known for his active support for Latin American liberation theology. He is Professor Emeritus of Ethics, Philosophy of Religion, and Ecology at the Rio de Janeiro State University. In 2001, he received the Right Livelihood Award for "his inspiring insights and practical work to help people realise the links between human spirituality, social justice and environmental stewardship."

Latin American liberation theology is a synthesis of Christian theology and Marxian socio-economic analyses, that emphasizes "social concern for the poor and political liberation for oppressed peoples". Beginning in the 1960s after the Second Vatican Council, liberation theology became the political praxis of Latin American theologians such as Gustavo Gutiérrez, Leonardo Boff, and Jesuits Juan Luis Segundo and Jon Sobrino, who popularized the phrase "preferential option for the poor". It arose principally as a moral reaction to the poverty and social injustice in the region, which Cepal deemed the most unequal in the world.