Nyāya is the premier realist school of philosophy in classical India. It is also the home of a sophisticated epistemology and natural theology. This dissertation presents a distinctive interpretation of Nyāya’s epistemology and considers how it may be developed in response to various classical and contemporary challenges. I argue that it is best understood as a type of reliabilism, provided relevant qualifications. Moreover, I show that a number of apparently distinct features of Nyāya’s approach to knowledge tightly cohere when seen as components of a thoroughgoing epistemological disjunctivism. I defend Nyāya epistemology as a viable contemporary option, illustrating how it avoids problems faced by generic reliabilism. In the second portion of the dissertation, I examine the way in which Nyāya’s knowledge sources (perception, inference, and testimony) are deployed in support of a theistic metaphysics, highlighting Nyāya’s principled extension of its views of knowledge acquisition. In an appendix, I provide a full translation and commentary on an argument for God’s existence by Vācaspati Miśra (a 10th century philosopher who is unique in having shaped several distinct schools), found in his commentary on Nyāya-sūtra.