This book constitutes the proceedings of the 22nd Asian Symposium on Programming Languages and Systems, APLAS 2024, held in Kyoto, Japan, during October 22-24, 2024. The 18 full papers presented here were carefully reviewed and selected from 37 submissions. These papers have been categorized under the following topical sections: Type theory and Semantic Frameworks; Probabilistic and Declarative Programming; Quantum Computation; Logical Relations; Verification.