PurposeExamine the impact of the EXercise for Cancer to Enhance Living Well's (EXCEL) 10–12-week exercise and behaviour change support intervention on secondary effectiveness outcomes, including patient-reported outcomes, physical function, and program satisfaction. MethodsIndividuals with cancer up to 3 years post treatment with any tumour type were eligible. Outcomes were measured at baseline and immediately following the 10–12-week intervention. Patient-reported outcomes included participant characteristics, overall well-being, cognition, fatigue, symptom severity, exercise barrier self-efficacy, and program satisfaction. Physical function included shoulder flexion, 30-s sit to stand, sit and reach, 2-min step test or 6-min walk test (in-person only), and single leg balance. Wilcoxon signed-rank tests were used to assess changes in patient-reported outcomes and physical function assessments from baseline to 12-weeks. ResultsA total of 804 participants enrolled in the study in the first 2.5-years, with 699 completing the intervention. Wilcoxon signed rank tests and Rosenthal coefficients (r) showed significant (p < 0.05) small improvements in well-being (r = 0.10), fatigue (r = 0.25), symptom severity (r = 0.17), and self-efficacy (r = 0.11). Significant (p < 0.01) moderate to large improvements were observed for the 30-s sit to stand (r = 0.54), sit and reach (left: r = 0.46; right: r = 0.41), 2-min step test (r = 0.66), 6-min walk test (r = 0.52), and single leg balance (left: r = 0.32; right: r = 0.34) assessments. Participants reported high satisfaction with program staff (average = 4.5/5) and that the program was beneficial and enjoyable (average = 4.6/5). ConclusionEXCEL's group-based exercise program with behaviour change support, delivered in an online supervised setting to individuals living with cancer, may improve patient-reported outcomes and physical function and is associated with high participant satisfaction.