Phonology is the systematic study of the sounds used in language, their internal structure, and their composition into syllables, words, and phrases. Computational phonology is the application of formal and computational techniques to the representation and processing of phonological information. This chapter presents the fundamentals of phonology along with an overview of computational phonology. Fundamentals discussed include phonological features, phonemes, early generative grammar, autosegmental phonology, syllable structure, and optimality theory. Finite-state machines, attribute-value matrices, computational learning methods, and existing software toolkits round out the discussion on comptuational phonology.