This thesis examines the relationship between goal conflict, ruminative thinking, and psychological distress. It is presented in three parts. Part 1 presents a systematic review of the existing literature on the association between goal conflict and depression in non-clinical adults. Findings from 12 studies were synthesised. The evidence to support the relationship between goal conflict and depression was not consistent, and this association appeared to be relatively weak. The findings provided some clinical implications, albeit limited, as more research on this subject in clinical populations remains needed. Part 2 presents an empirical paper examining the associations among goal conflict, ruminative thinking, and aspects of psychological distress in a non-clinical adult sample. Participants were asked to complete a set of questionnaires on ruminative thinking, psychological symptoms, and sense of control. They were also asked to rate how conflicting their goals were to one another. The findings suggest that individuals with higher levels of goal conflict ruminate more than those experiencing lower goal conflict, and that ruminative thinking appears to be positively correlated with symptoms of depression, anxiety, and stress. However, the findings did not support that ruminative thinking is a mediator between goal conflict and psychological symptoms. Perceived constraints (a subcomponent of sense of control) also did not moderate the impact of goal conflict on ruminative thinking. Part 3 is a critical appraisal of the empirical paper. This consists of my reflection on the research process, as well as my personal experience related to the subject of goal conflict while conducting this project.