Dear Colleagues, We announce the 2025 challenge sponsored by The Algonauts Project <https://algonautsproject.com/>: How the Human Brain Makes Sense of Multimodal Movies. We invite you to join us in this competition to develop the best brain encoding models that are multimodal and that well generalize beyond their training distribution. The challenge is based on data from CNeuroMod <https://www.cneuromod.ca/>, the largest dataset of human brain fMRI responses to multimodal movies. Participants whose models most closely match recorded brain data (top 3) will receive monetary prizes for a total of 17,000 € (1st 9,000 €; 2nd 5,000 €; 3rd 3,000 €), and will be invited to present their winning models at this year’s Cognitive Computational Neuroscience (CCN) <https://2025.ccneuro.org/> conference, in Amsterdam, in August 2025. The challenge is open to all, and provides transparent, directly comparable results through a public leaderboard that is updated automatically after each submission to facilitate rapid model assessment and guide development. Submission deadline: July 13, 2025 Website: https://algonautsproject.com/ Email: algonauts.mit@gmail.com Bluesky: @algonautsproject.bsky.social <https://bsky.app/profile/algonautsproject.bsky.social> X: @AlgonautsProj <https://x.com/AlgonautsProj> We look forward to your participation in the challenge! The Algonauts Project Team Algonauts Project 2025 Challenge Team: Alessandro Gifford, Freie Universität Berlin Domenic Bersch, Goethe University Frankfurt Marie St-Laurent, CRIUGM Basile Pinsard, CRIUGM Julie Boyle, Université de Montréal Lune Bellec, Université de Montréal Aude Oliva, Massachusetts Institute of Technology Gemma Roig, Goethe University Frankfurt Radoslaw Cichy, Freie Universität Berlin