Proceedings Ninth International Symposium on Games, Automata, Logics, and Formal Verification

This volume contains the proceedings of the Ninth International Symposium on Games, Automata, Logic and Formal Verification (GandALF 2018). The symposium took place in Saarbr\"ucken, Germany, from the 26th to the 28th of September 2018. The GandALF symposium was established by a group of Italian computer scientists interested in mathematical logic, automata theory, game theory, and their applications to the specification, design, and verification of complex systems. Its aim is to provide a forum where people from different areas, and possibly with different backgrounds, can fruitfully interact. GandALF has a truly international spirit, as witnessed by the composition of the program and steering committee and by the country distribution of the submitted papers.