Resting sinus tachycardia is frequently encountered in cancer patients. It affects a wide variety of cancer patients and is associated with distressing symptoms. Cancer-associated resting sinus tachycardia varies in its underlying mechanism. It can stem from the tumor burden or the side effects of chemotherapy/radiotherapy, or it can be secondary to paraneoplastic syndrome or the sequalae of cancer itself (infection, anemia, thrombosis, etc.). The clinical significance of resting sinus tachycardia extends beyond mere symptomatology, as it can potentially indicate severe complications which may facilitate or exacerbate a new or underlying cardiovascular dysfunction. Therefore, this necessitates thorough diagnostic tools to discern the underlying cause and tailor appropriate management strategies, whether pharmacological, non-pharmacological, or conservative. While resting sinus tachycardia has been extensively investigated in the context of cardiovascular disease, its underlying etiology, clinical implication, prognostic value, and treatment options remain vague in the context of cancer. This review aims to explore the topic of resting sinus tachycardia in cancer patients through delving deeper into its underlying mechanism, presenting the current evidence on its effect on cancer-independent cardiovascular and all-cause mortality, as well as providing some insight into the currently available treatment options. It will also propose therapeutic interventions and strategies aimed at optimizing cancer patient care. Lastly, it will highlight research gaps which need to be addressed further, as future research is needed to refine the diagnostic criteria, develop targeted therapies, find alternative cardioprotective/cardio-neutral chemotherapy options, and establish evidence-based guidelines to improve outcomes in this vulnerable patient population.