This book constitutes the proceedings of the 24th Asian Symposium on Programming Languages and Systems, APLAS 2026, held in Hong Kong, China, during December 1–4, 2026.

The 15 full papers included in this book were carefully reviewed and selected from 34 submissions. They were organized in topical sections as follows: Type Systems and Categorical Semantics; Static Analysis and Program Verification; WebAssembly Semantics and Analysis; Language Implementation and Metaprogramming; Automata and Process Algebra.