<p>This study investigated the association between common mental disorders (CMD) and sleep parameters measured objectively through actigraphy, as well as using self-reported data, among female shift workers in southern Brazil. This cross-sectional study involved 450 female participants, with 278 undergoing actigraphy. CMD was assessed using a Self-Reporting Questionnaire (SRQ-20), while self-reported sleep disturbance was measured using the Pittsburgh Sleep Quality Index (PSQI) scale. Actigraphy was utilized to measure sleep quality over a consecutive 48-h period. The odds ratios (OR) and 95% confidence intervals (CI) were estimated using multinomial logistic regression. The prevalence of sleep disturbance was 9.7% (95% CI 7.2–12.9) according to the PSQI, while CMD prevalence was 47.3% (95% CI 42.6–52.1) in the entire sample. Sleep disturbance was significantly associated with positive CMD screening (OR = 20.03; 95% CI 7.22–55.54) as well as with night shift work (OR = 5.38; 95% CI 1.75–16.52). CMD did not exhibit a statistically significant association with objective sleep quality parameters measured using actigraphy. However, adjusted analysis of sleep efficiency revealed that women on the afternoon (OR = 3.09; 95% CI 1.53–6.25) or night shifts (OR = 3.43; 95% CI 1.60–7.35) had a higher prevalence of 10 or more awakenings during sleep compared to those working morning shifts. This study highlights the high prevalence of CMD among female shift workers. Furthermore, CMD demonstrated a statistically significant association with self-reported sleep disorders within this population group. However, this association was not observed when compared with objective data collected by actigraphy.</p>