Patients' outcomes and experience of health care can be improved through the systematic capture and use of information from their perspective. We are currently not using all the information we could gain from Patients' outcomes and experience of health care can be improved through the systematic capture and use of information from their perspective. We are currently not using all the information we could gain from Patient-Reported Outcomes (PROs) to accurately measure value from the patient perspective. This is due to the lack of standardisation, interoperability and implementation of PRO measurement schemes. We urgently need a European scale network of outcomes data collection, analysis and evidence sharing to inform clinical practice and healthcare decisions. To tackle these issues, this public-private consortium brings together scientists, clinicians and professionals to design and set up independent, patient-centred, Health Outcomes Observatories (H2Os). With input from patients, providers and health care decision makers (health ministries, health insurers, regional health authorities, public health agencies, medicines regulators, health technology assessment agencies), these Observatories will collect data and provide information not only for individual clinical care, but also for evaluation of new technologies and for healthcare decision making. We will establish ethically and legally sound national, or regional, H2Os and run these initially in four countries for three diseases. Based on a hybrid model of federated and centralised data collection, management and analysis, these Observatories will operate under a governance model that will guarantee that data are protected under jurisdictional data protection law. H2Os will be connected to a pan-European umbrella H2O to facilitate interoperability, guide reproducibility in other countries, and promote the benefit of measuring and using patient-centred outcomes at regional, national, European and global levels.