Dear colleagues, The 35th International Conference on User Modeling, Adaptation, and Personalization (ACM UMAP 2027) will take place in Chicago, USA, from June 9 to 12, 2027. ACM UMAP 2027 will be a fully in-person, on-site conference. UMAP 2027 continues to be the leading international conference bringing together research in AI and HCI to support effective human-AI collaboration via interactive systems that can model, adapt, and personalize to their users. We invite proposals for workshops to be held in conjunction with UMAP 2027. Traditionally, workshops provide additional forums for participants to engage in focused discussions and explore key emerging areas of the conference topics; they provide a setting for researchers and practitioners from industry and academia to share ideas and seed new research trajectories. For UMAP 2027, our goal is to curate a diverse and balanced workshop program that reflects the breadth and depth of the UMAP community, accommodating newly emerging, currently evolving, and historically understudied research topics. We welcome both full and half-day workshops of different formats: from traditional, mini-conference-style events with their own submission and peer-review process, to more interactive and hands-on formats. These may include moderated discussions, collaborative writing sessions, hackathon-style resource development, or design-thinking workshops that encourage active participation. **Important dates (11:59 PM AoE: Anywhere on Earth)** * **Submission deadline:** December 11, 2026 * **Notification:** January 15, 2027 * **Workshop website URL submission:** February 5, 2027 * **Workshop Days:** June 9, 2027 More information, including submission instructions and template requirements, is available at: https://um.org/umap2027/call-for-workshop-proposals/ Please feel free to share this Call for Workshop Proposals with colleagues and researchers who may be interested. Best regards, The ACM UMAP 2027 Organizing Committee *We apologize if you receive multiple copies of this CfP.*