Background: Britain is rich in longitudinal population cohort studies that posit valuable data resources for social science. However, education researchers currently underutilize these resources. Aims: The current paper (1) outlines the power and benefits of secondary data analyses for educational science and (2) provides a practical guide for education researchers on the characteristics, data, and accessibility of British population cohort studies. Methods: We identified eight British population cohort studies from the past 40 years that collected scholastic performance data during primary and secondary schooling, including (1) Avon Longitudinal Study of Parents And Children (ALSPAC), (2) Twins Early Development Study (TEDS), (3) Effective Pre-School, Primary and Secondary Education Project (EPPSE), (4) Millennium Cohort Study (MCS), (5) Born in Bradford (BiB), (6) Next Steps (LYSPE1), (7) Understanding Society (US), and (8) Our Future (LYSPE2). Participants across these studies were born between 1989 and 2010, and followed up at least once and up to 68 times, over periods of 7 to 29 years. For each study, we summarize here the context and aims, review the assessed variables, and describe the process for accessing the data. Conclusions: We hope this article will encourage and support education researchers to widely utilize existing population cohort studies to further advance education science in Britain and elsewhere.