This book constitutes the proceedings of the 17th IAPR International workshops on Document Analysis Systems, DAS 2026, which took place in conjunctions with ICDAR 2026, in Vienna, Austria, during September 3-4, 2026. The 29 full papers included in this book were carefully reviewed and selected from 50 submissions. They were organized in topical sections as follows: Tables, Forms and Structured Extraction; Document-Centric AI, Retrieval and REasoning; Handwriting, Writer Identification and Music Documents; OCR, Layout and Recognition Systems; Enterprise and Industrial Document AI; and Historical, Symbolic and Camera-Based Documents.