This BIC-TA 2025 proceedings constitutes the refereed post-conference proceedings of the 20th International Conference on Bio-Inspired Computing: Theories and Applications, BIC-TA 2025, held in Wuhan, China, during November 7–9, 2025.The 50 full papers presented in these proceedings were carefully reviewed and selected from 124 submissions. The papers are organized in the following topical sections: Biological Computing; Engineering Application; Evolutionary Computation; Neural Computing.