The purpose of this study is to investigate how well-being changes over the adult life course from early adulthood in 1998 through to the COVID-19 pandemic in 2021. We identify diverse well-being trajectories over time in a cohort of British Columbians and explore the extent to which changes in well-being associated with the pandemic varied for individuals in these different trajectory groups. Specifically, we ask: what was the effect of the pandemic on the well-being of individuals with different prior well-being trajectories over adulthood and how were these effects related to personal, educational and employment factors? To address this question, we model well-being trajectories over a large span of adulthood from the age of 28 to 51 years old. We find a diversity of distinct patterns in well-being changes over adulthood. The majority experience high well-being over time, while almost one in five experiences either chronically low or drastically decreased well-being in mid-adulthood, which coincides with the pandemic. Notably, those who have completed post-secondary education are less likely to report low well-being trajectories. Those with the lowest well-being over time also report the largest negative effects of the pandemic, which illustrates the compounding effects of the pandemic on existing inequalities.