This five-volume set, LNCS 16985-16989, constitutes the refereed proceedings of the 19th International Conference on Parallel Problem Solving from Nature, PPSN 2026, held in Trento, Italy, during August 29-September 2, 2026. The 165 full papers presented in these proceedings were carefully reviewed and selected from 527 submissions. The papers cover the following topical sections: Part I: Theory & Runtime Analysis; Combinatorial Optimization; Landscape Analysis & Benchmarking; Part II: Multi-Objective Optimization; Swarm Intelligence & ACO; Part III: Evolution Strategies & Continuous Black-Box Optimization; Bayesian & Surrogate-Assisted Optimization; Quantum Optimization & Computing; EC for ML, Data Science & Domain Applications; General EA Methodology, Operators & Parallel EC; Part IV: Genetic Programming & Symbolic Regression; Quality-Diversity & Novelty Search; Robotics, Morphology & Design Encoding; Coevolution & Evolutionary Dynamics; Part V: RL, Hyper-heuristics & Algorithm Selection; LLMs + Evolutionary Computation; Neural Architecture Search, AutoML & Neuroevolution.