In linguistics, romanization or latinization (or romanisation/latinisation: see spelling differences) is the representation of a written word or spoken speech with the Roman (Latin) script, or a system for doing so, where the original word or language uses a different writing system (or none). Methods of romanization include transliteration, for representing written text, and transcription, for representing the spoken word. The latter can be subdivided into phonemic transcription, which records the phonemes or units of semantic meaning in speech, and more strict phonetic transcription, which records speech sounds with precision. Each romanization has its own set of rules for pronunciation of the romanized words.

If the romanization attempts to transliterate the original script, the guiding principle is a one-to-one mapping of characters in the source language into the target script, with less emphasis on how the result sounds when pronounced according to the reader's language. For example, the Nihon-shiki romanization of Japanese allows the informed reader to reconstruct the original Japanese kana syllables with 100% accuracy, but requires additional knowledge for correct pronunciation.