This chapter traces the historical development of person-reported outcome measures (PROMs) and experience measures (PREMs) from early pioneers to the twenty-first century. The journey began in the eighteenth century during the Scottish Enlightenment and continued through Florence Nightingale’s nineteenth-century hospital classification system, advocating for transparency in patient outcomes. The twentieth century saw innovations like Ernest Codman’s End Results system for surgical outcomes, and the Apgar score, measuring newborn health. The 1980s introduced Quality-Adjusted Life Years (QALYs) and patient-reported outcomes, driven by the need for better resource allocation and cost-effectiveness. PROMs like the SF-36 and EQ-5D became standard tools in the 1990s, especially within pharmaco-economics and regulatory frameworks. By the 2000s, political and organizational initiatives, such as the NHS quality mandates and the Triple Aim framework, cemented PROMs as essential tools for improving healthcare quality, patient experience, and cost-effectiveness. History continues to shape current approaches to measuring health outcomes globally.