This volume constitutes the proceedings of the 17th International Conference of the CLEF Association on Experimental IR Meets Multilinguality, Multimodality, and Interaction, CLEF 2026, held in Jena, Germany, during September 2026. 

The proceedings contain 11 full and 3 short conference papers accepted from 27 submissions. Furthermore, 6 best of CLEF 2025 Labs' papers, 1 Past, Present, Future paper and 16 Lab overview papers are presented. The CLEF conference and labs of the evaluation forum deal with topics in information access from different perspectives, in any modality and language, focusing on experimental information retrieval (IR).