Fatigue is a common problem faced by cancer patients and survivors, yet is often overlooked. An online fatigue class is evaluated using measures based on the Health Belief Model (HBM). A sample of 26 survivors and seven caregivers completed pre-class and post-class surveys and a facilitated discussion. Statistically significant improvements were detected in both the fatigue knowledge (p < 0.001) and belief (p < 0.001) scores. Participants reported that the content was accessible and useful. The class had a positive impact on their knowledge and beliefs about cancer fatigue. This suggests that HBM may be an appropriate framework for the evaluation of Internet-based educational interventions.