This book constitutes the thoroughly refereed revised selected papers of the 19th International Symposium on Trends in Functional Programming, TFP 2018, held in Gothenburg, Sweden, in June 2018. The 7 revised full papers were selected from 13 submissions and present papers in all aspects of functional programming, taking a broad view of current and future trends in the area. It aspires to be a lively environment for presenting the latest research results, and other contributions, described in draft papers submitted prior to the symposium.