Objective There is growing recognition in psychology that wellness is more than the absence of disease and distress. Well‐being has been defined in numerous ways. Two dominant models include Diener, Eunkook, Suh, Lucas and Smith's (1999) model of subjective well‐being (SWB) and Ryff's (1989) model of psychological well‐being (PWB). In contrast to the abundance of research investigating negative constructs and psychopathology in chronic fatigue syndrome (CFS), there has been a paucity of positive psychology studies. This study had two aims: to examine PWB and SWB and their relationship to symptoms in CFS and to compare PWB scores in a subgroup of the CFS sample to a matched control group. Method Chronic fatigue syndrome participants (n = 60) completed self‐report scales of PWB, SWB, fatigue, anxiety and depression. PWB scores in a subgroup of the CFS sample (n = 42) were compared with those of a matched nonclinical control group (n = 42). Results Correlations between scales of symptoms and well‐being were complex. Well‐being dimensions were largely independent of physical components of fatigue but strongly related to psychological components of fatigue and psychological distress. Multiple regression indicated that five dimensions of well‐being uniquely predicted symptomatology. Compared with the control group, the CFS group scored significantly lower on five of Ryff's six PWB dimensions, with particularly marked deficits in personal growth, environmental mastery and self‐acceptance. Conclusion This multidimensional assessment of well‐being advances our understanding of CFS and offers new treatment targets. Future research must investigate whether interventions targeting theses well‐being deficits can boost the efficacy of symptom‐focused treatments. Copyright © 2016 John Wiley & Sons, Ltd. Key Practitioner Messages Previous psychological research into CFS has largely focused on the identification of negative constructs and CBT, a treatment that targets evidenced‐based negative constructs, has demonstrated efficacy in reducing levels of fatigue and disability. However, the majority of people continue to experience psychiatric symptoms and excessive levels of fatigue post‐treatment. Finding ways to enhance the efficacy of existing treatments is a clinical priority. There is evidence to suggest that in clinical populations, standard CBT is effective at reducing negative affect and thinking but fails to enhance low levels of positive affect and thinking, implying treatments may be more effective if they promote positive functioning alongside a reduction of negative functioning. Multidimensional models of well‐being suggest that well‐being is not a single phenomenon, and different psychological disorders may be characterized by varying well‐being deficit profiles. Psychological well‐being was found to be diminished in CFS participants compared with controls, with particularly marked deficits in personal growth, environmental mastery and self‐acceptance, suggesting that these may be particularly important treatment targets. Well‐being dimensions within the CFS group were largely independent of physical symptoms but strongly related to psychological symptoms, suggesting what may be causing low levels of well‐being in CFS is largely psychological factors and the general impact of living with a chronic illness rather than symptom levels per se.