OBJECTIVE: Mindfulness-based interventions (MBIs) are increasingly being integrated into oncological treatment to mitigate psychological distress and promote emotional and physical well-being. This review aims to provide the most recent evaluation of Mindfulness-Based Stress Reduction (MBSR), Mindfulness-Based Cognitive Therapy (MBCT), and Mindfulness-Based Cancer Recovery (MBCR) treatments, in reducing symptoms of depression, anxiety and CRF in oncology populations. METHODS: A search using the following search terms was conducted: (mindful* OR mindfulness* OR mindfulness-based* OR MBI* OR MBCT OR MBSR OR MBCR) AND (Oncol* OR cancer OR neoplasm OR lymphoma OR carcinoma OR sarcoma) to obtain relevant publications from five databases: PsycINFO, PubMed, Embase, and MEDLINE by EC, and ProQuest Dissertations & Theses Global from January 2000 to February 2022. 36 independent studies (n = 1677) were evaluated for their overall effect sizes (using random-effects models), subgroup analyses, and quality appraisals. Evaluations were performed separately for non-randomized (K = 20, n = 784) and randomized controlled trials (K = 16, n = 893). RESULTS: The results showed that MBIs have significant medium effects in reducing symptoms of depression (Hedges' g = 0.43), anxiety (Hedges' g = 0.55) and CRF (Hedges' g = 0.43), which were maintained at least three months post-intervention. MBIs were also superior in reducing symptoms of anxiety (Hedges' g = 0.56), depression (Hedges' g = 0.43), and CRF (Hedges' g = 0.42) in oncology samples relative to control groups. The superiority of MBIs to control groups was also maintained at least three months post-intervention for anxiety and CRF symptoms, but not for depressive symptoms. The risk of bias of the included studies were low to moderate. CONCLUSIONS: This review found that MBIs reduced symptoms of depression, anxiety and CRF in oncology populations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: International Prospective Register of Systematic Reviews: CRD42020143286.