Fatigue is commonly reported among adults with cerebral palsy (CP) and in the general population. The aim of this study was to examine the prevalence of perceived fatigue in adults with CP compared with the general Norwegian population. A multidimensional questionnaire, containing among other instruments the Fatigue Questionnaire, was sent to persons with CP aged 18 years or older with no intellectual disabilities documented in their medical records. Results were compared with recently published results of a study of fatigue in the general population in Norway. There were 406 respondents (209 males, 197 females; mean age 34 years, SD 11 years; age range 18 to 72 years). Distribution of the different types of CP coincided with international epidemiological studies on CP. Adults with CP reported significantly more physical, but not more mental fatigue, than the general population. The strongest predictors associated with fatigue were bodily pain, deterioration of functional skills, limitations in emotional and physical role function, and low life satisfaction. Fatigue was not significantly associated with type of CP but was most prevalent in persons with a self-reported moderate grade of CP. Results of the present study indicate that physical fatigue is a pronounced problem in adults with CP, which has an impact on the preservation of functional skills and life satisfaction. Fatigue and factors related to fatigue should be addressed specifically in follow-up programmes for persons with CP.