This book constitutes the refereed proceedings of the 11th International Conference on Language and Automata Theory and Applications, LATA 2017, held in Umeå, Sweden, in March 2017. The 31 revised full papers presented together with 4 invited talks were carefully reviewed and selected from 73 submissions. The papers cover the following topics: algorithmic learning and semantics; automata and logics; combinatorics on words, compression, and pattern matching; complexity; finite automata; grammars, languages, and parsing; graphs and Petri Nets; non-classical automata; and pushdown automata and systems.