In 1538–39 Francisco de Vitoria delivered two relections: De Indis and De iure belli. This article distills from these writings the topic of free trade as a “human right” in accordance with ius gentium or the “law of peoples.” The right to free trade is rooted in a more fundamental right to communication and association. The rights to travel, to dwell, and to migrate precede the right to trade, which is also closely connected to the rights to preach, to protect converts, and to constitute Christian princes. This has significant repercussions on the field of business ethics: the right to free trade is ultimately founded directly on natural law and indirectly on divine law; trade is not independent of ethics; and trade is presented as an opportunity to develop the virtues of justice and friendship, among other repercussions. Vitoria is portrayed as a defender of private initiative and free markets.