BACKGROUND: The study objective is to identify risk factors associated with fatigue among long-term OPC survivors. METHODS: This cross-sectional study included disease-free OPC survivors treated curatively between 2000 and 2013 who were surveyed from September 2015 to July 2016. The outcome variable was patient-reported fatigue. Multivariable logistic regression was used to identify factors associated with moderate to severe fatigue. RESULTS: Among 863 OPC survivors, 17.4% reported moderate to severe fatigue. Self-reported thyroid problems (OR: 2.01; p = 0.003), current cigarette smoking at time of survey (OR: 3.85; p = 0.001), late lower cranial neuropathy (OR: 3.44; p = 0.002), and female sex (OR: 1.91; p = 0.010) were concurrent risk factors of reporting moderate to severe fatigue. Ipsilateral intensity-modulated radiotherapy (OR: 0.18; p = 0.014) was associated with lower risk of reporting moderate to severe fatigue. CONCLUSIONS: Our study identified thyroid problems, smoking, and late lower cranial neuropathy as associated with moderate to severe fatigue. These findings should be further validated in prospective studies to address fatigue among OPC survivors.