Cancer represents a major global public health challenge, and its treatments, such as chemotherapy and radiotherapy, are frequently associated with adverse effects. Among these, oral mucositis (OM) stands out as a debilitating inflammatory condition that compromises quality of life and may lead to interruption of cancer therapy. Given the limited efficacy of conventional treatments, propolis has been investigated as a natural therapeutic alternative due to its antioxidant, anti-inflammatory, and antimicrobial properties. This narrative literature review, conducted between 2012 and 2025, included studies indexed in the Public Medical Database (PubMed), Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Google Scholar, and ClinicalTrials.gov databases. We analyzed clinical trials that evaluated different forms of propolis administration, such as gel, mouthwashes, oral solutions, and topical applications, in patients with various types of cancer undergoing radiotherapy, chemotherapy, or combined treatment. The results demonstrated a significant reduction in pain, dysphagia, dysgeusia, and OM severity, as well as a delay in the onset and progression of lesions, with a low incidence of adverse effects. However, variability in the chemical composition of propolis and the lack of standardized protocols still limit the reproducibility and comparability of the findings. Overall, these results reinforce the therapeutic potential of propolis for the prevention and treatment of OM in oncology patients, while underscoring the need for long-term, randomized clinical trials to establish optimal concentrations, pharmacological formulations, and standardized application protocols.