Introduction:Data and digital infrastructure drive collaboration and help develop integrated healthcare systems and services. COVID-19 induced changes to collaboration between healthcare organisations, which previously often happened in fragmented and competitive ways. New collaborative practices relied on data and were crucial in managing coordinated responses to the pandemic. In this study, we explored data-driven collaboration between European hospitals and other healthcare organisations in 2021 by identifying common themes, lessons learned and implications going forward.Methods:Study participants were recruited from an existing Europe-wide community of mid-level hospital managers. For data collection, we ran an online survey, conducted multi-case study interviews and organised webinars. Data were analysed using descriptive statistics, thematic analysis and cross-case synthesis.Results:Mid-level hospital managers from 18 European countries reported an increase in data exchange between healthcare organisations during the COVID-19 pandemic. Data-driven collaborative practices were goal-oriented and focused on the optimisation of hospitals’ governance functions, innovation in organisational models and improvements to data infrastructure. This was often made possible by temporarily overcoming system complexities, which would otherwise hinder collaboration and innovation. Sustainability of these developments remains a challenge.Discussion:Mid-level hospital managers form a huge potential of reacting and collaborating when needed, including rapidly setting up novel partnerships and redefining established processes. Major post-COVID unmet medical needs are linked to hospital care provision, including diagnostic and therapeutic backlogs. Tackling these will require rethinking of the position of hospitals within healthcare systems, including their role in care integration.Conclusion:Learning from COVID-19-induced developments in data-driven collaboration between hospitals and other healthcare organisations is important to address systemic barriers, sustain resilience and further build transformative capacity to help build better integrated healthcare systems.