The 9th International ABZ Conference on Rigorous State-Based Methods, 2023 (ABZ 2023) covers various state-based approaches to formal methods, including Alloy, ASM, the B-Method, TLA, VDM, and the Z notation. The conference is to be held in Nancy, France↑, during 30 May to 2 June 2023, organized by Loria, University of Lorraine↑.