This book constitutes the refereed proceedings of the 13th International Conference, NooJ 2019, held in Hammamet, Tunisia, in June 2019. NooJ is a linguistic development environment that allows linguists to formalize several levels of linguistic phenomena. NooJ provides linguists with tools to develop dictionaries, regular grammars, context-free grammars, context-sensitive grammars and unrestricted grammars as well as their graphical equivalent to formalize each linguistic phenomenon. The 18 full papers presented were carefully reviewed and selected from 54 submissions. The papers are organized in the following tracks: Development of Linguistic Resources, Natural Language Processing Applications, NooJ for the Digital Humanities.