Objective To evaluate fatigue frequency and severity among patients with psoriatic arthritis (PsA) and assess the effect of fatigue severity on patient-reported outcome measures (PROMs) assessing quality of life, function, and work productivity. Methods Data were derived from the Adelphi Disease Specific Programme, a cross-sectional survey conducted in 2018 in the United States and Europe. Patients had physician-confirmed PsA. Fatigue was collected as a binary variable and through its severity (0-10 scale, using the 12-item Psoriatic Arthritis Impact of Disease fatigue question) from patients; physicians also reported patient fatigue (yes/no). Other PROMs included the 5-level EuroQol 5-dimension questionnaire (EQ-5D-5L) for health-related quality of life (HRQOL), Health Assessment Questionnaire\textendash Disability Index, and Work Productivity and Activity Impairment Questionnaire. Multivariate linear regression was used to evaluate the association between fatigue severity and other PROMs. Results Among the 831 included patients (mean age 47.5 yrs, mean disease duration 5.3 yrs, 46.9% female, 48.1% receiving a biologic), fatigue was reported by 78.3% of patients. Patients with greater fatigue severity had greater disease duration, PsA severity, pain levels, body surface area affected by psoriasis, and swollen and tender joint counts (all P < 0.05). In multivariate analyses, patients with greater fatigue severity experienced worse physical functioning, HRQOL, and work productivity (all P < 0.001). Presence of fatigue was underreported by physicians (reported in only 32% of patients who self-reported fatigue). Conclusion Prevalence of patient-reported fatigue was high among patients with PsA and underrecognized by physicians. Fatigue severity was associated with altered physical functioning, work productivity, and HRQOL.