Rapid progress in information and biotechnologies offers the promise of better, personalized health strategies using rich phenotypic, environmental and molecular (omics) profiles of every individual. To capitalize on this great promise, key challenge is to relate these profiles to health and disease while accounting for high diversity in individuals, populations and environments. Both Europe and Canada have long-term investments in population-based prospective cohort studies providing essential longitudinal data. These data must be analysed in unison to reach statistical power, however, presently cohort data repositories are scattered, hard to search and integrate, and data protection and governance rules discourage central pooling. EUCAN-Connect will enable large-scale integrated cohort data analysis for personalized and preventive healthcare across EU and Canada. This will be based on an open, scalable data platform for cohorts, researchers and networks, incorporating FAIR principles (Findable, Accessible, Interoperable, Reusable) for optimal reuse of existing data, and building on maturing federated technologies, with sensitive data kept locally and only results being shared and integrated, in line with key ELSI and governance guidelines. Widespread uptake will be promoted via beyond state-of-the-art research in close collaboration with leading cohort networks, focused on early-life origins of cardio-metabolic, developmental, musculoskeletal and respiratory health and disease impacting human life course. To address challenges of sustainability and curation, we will deliver innovative solutions for distributed, low-cost data harvesting and preservation, community curation/harmonization, privacy protection, open source bioinformatics toolbox development, and international governance. EUCAN-Connect platform and collaborations will be coordinated through BBMRI-ERIC (EU) and Maelstrom Research (Canada) to sustain long-term benefits to science and citizens worldwide.