  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.
