The 4-volume set LNCS 16972-16975 constitutes the proceedings of the 20th International Conference on Document Analysis and Recognition, ICDAR 2026, which took place in Vienna, Austria, from August 31 to September 2, 2026. The 140 full papers included in the proceedings were carefully reviewed and selected from 300 submissions. In addition, this proceedings includes 8 competition reports which were also reviewed, separately from the main submission process. The papers were organized into topical sections as follows: Part I: Document Analysis Systems; Document Forensics and Provenance; Document Image Processing; Benchmarks and Datasets; Graphics Recognition; Handwriting Recognition; Historical Document Analysis; Layout Analysis; Recognition of Tables and Formulas; Text and Symbol Recognition; Part II: Poster Papers; Part III: Poster Papers; Part IV: Poster Papers; Competitions.