Low-quality and precarious employment have been associated with adverse mental health and wellbeing. More evidence is needed on how the quality of employment trajectories - including transitions in and out of unemployment, inactivity, and employment of varying quality - are associated with individuals' mental health over time. This paper aimed to derive a typology of multidimensional employment trajectories and assess associations with mental health in the UK. Data from waves 1-9 of the UK Household Longitudinal Study were used (2009-2019). Individuals aged 30-40 at baseline were included (N=1603). Using multichannel sequence and clustering analyses, we derived a typology of employment trajectories across employment statuses and four employment quality indicators. We assessed associations with subsequent psychological distress, accounting for baseline mental health. Changes in average General Health Questionnaire scores are described. A typology of five trajectory clusters highlighted stable and secure and precarious/low-quality trajectories for both men and women. Women who reported being economically inactive at most waves had higher odds of experiencing psychological distress than did women in 'standard' trajectories, regardless of baseline mental health. Women's scores of psychological distress in the 'precarious' group on average increased along their trajectories characterized by instability and transitions in/out of unemployment, before a move into employment. Men who likely moved in and out of unemployment and economic inactivity, with low probability of paid employment, reported increased psychological distress at the end of follow-up. This may partly be due to pre-existing mental ill-health. This paper shows the importance of high-quality employment for individuals' mental health over time. Researchers need to consider dynamic associations between employment quality and mental health across the life-course.