PURPOSE: To determine the pooled effect of exercise on the bone health of people diagnosed with cancer. METHODS: Four electronic databases were systematically searched. Controlled trials that assessed the effect of exercise on the bone mineral density (BMD) or content (BMC) measured by dual-energy x-ray absorptiometry or peripheral quantitative computed tomography in people who had been diagnosed with cancer were included in the study. Random-effect meta-analyses of effect size (ES) were conducted. Sub-group analyses were performed to explore the influence of intervention duration, prescription and participant characteristics. RESULTS: Of 66 full-text articles screened, 22 studies, from 21 interventions, were included (primarily breast/prostate cancer, sample range n = 36-498). When all interventions were grouped, a significant pooled ES was observed for exercise on hip (ES = 0.112, 95% CI: 0.026 to 0.198; p = 0.011) and lumbar spine BMD (ES = 0.269, 95% CI: 0.036 to 0.501; p = 0.024) compared to control. There was also an influence of sex, where females had greater improvements in hip (ES = 0.120, 95% CI: 0.017 to 0.223; p = 0.022) and spine BMD (ES = 0.415, 95% CI: 0.056 to 0.774; p = 0.23) compared to males. CONCLUSION: Overall, exercise regimens of studies included in this review appear to improve bone health at the hip and spine in people diagnosed with cancer. Sub-analyses suggest some influence of sex, where females had greater improvements in BMD compared to males. It is essential that future studies evaluate the dose-response of exercise training on bone health and create exercise protocols that better align with the laws of bone modelling to enhance osteogenic potential.