Several psychological factors have been proposed to be associated with functional somatic disorders (FSD). However, large population-based studies investigating the importance of both personality and adverse life events (ALE) are sparse. This study aimed to investigate the association between FSD and neuroticism and the accumulated number of ALE, respectively. This cross-sectional study included a random sample of the adult Danish population (N = 7493). FSD were established by means of self-reported questionnaires and diagnostic interviews. Neuroticism was measured with the Danish version of the short-form NEO Personality Inventory. ALE were measured with the Danish version of the Cumulative Lifetime Adversity Measure. Strong positive associations were found between neuroticism and FSD, and ALE and questionnaire-based FSD. For interview-based FSD, strong positive associations were found for FSD, multi-organ type, and for the subtype of the general symptoms. The level of self-efficacy did not modify these associations, and no moderating effect of neuroticism and ALE in combination on the probability of having FSD was found. FSD were strongly associated with both neuroticism and the accumulated number of ALE, and these associations were not modified by self-efficacy. In combination, neuroticism and ALE did not have a moderating effect on the probability of having FSD.