This systematic review investigated randomized controlled trials evaluating cognitive behavioral therapy (CBT) and graded exercise therapy (GET) for adults with chronic fatigue syndrome (CFS). The objective was to determine prognosis following treatment. Studies were eligible if they were peer-reviewed and investigated treatment at least 12 weeks in duration. Studies were excluded if they used co-morbid diagnoses as entry criteria or if they did not measure fatigue, disability, or functioning. Literature published between 1988 and 2021 was searched using MEDLINE, EMBASE, PsycINFO, and Web of Science. Study quality was assessed using the Effective Public Health Practice Project assessment tool. Outcomes were synthesized when three or more studies reported outcomes obtained from the same validated measurement tool. The review included 15 publications comprising 1990 participants. Following CBT, and at short-term to medium-term follow-up, 44% considered themselves better and 11% considered themselves worse. Following GET, and at post-treatment to short-term follow-up, 43% considered themselves better and 14% considered themselves worse. These outcomes were 8–26% more favorable compared to control conditions. Two-thirds of studies were of moderate quality and the remainder were of weak quality. Limitations of this review relate to the clinical heterogeneity of studies and that most outcomes were self-reported. Results suggest some support for the positive effects of CBT and GET at short-term to medium-term follow-up although this requires further investigation given the inconsistent findings of previous reviews. Findings may not be generalizable to severe CFS. This review was registered with PROSPERO (CRD42018086002).