This book constitutes the proceedings of the 17th Latin American Symposium on Theoretical Informatics, LATIN 2026, which took place in Florianópolis, Brazil, during April 13–17, 2026.

The 42 full papers included in this book were carefully reviewed and selected from 103 submissions. They focus on algorithms, automata theory and formal languages, combinatorial optimization, complexity theory, computational biology, computational geometry, data compression, quantum computing, and theory of computing.