Global healthcare expenditure is escalating at an unsustainable rate. Money spent on medicines and managing medication-related problems continues to grow. The high prevalence of medication errors and inappropriate prescribing is a major issue within healthcare systems, and can often contribute to adverse drug events, many of which are preventable. As a result, there is a huge opportunity for pharmacists to have a significant impact on reducing healthcare costs, as they have the expertise to detect, resolve, and prevent medication errors and medication-related problems. The development of clinical pharmacy practice in recent decades has resulted in an increased number of pharmacists working in clinically advanced roles worldwide. Pharmacist-provided services and clinical interventions have been shown to reduce the risk of potential adverse drug events and improve patient outcomes, and the majority of published studies show that these pharmacist activities are cost-effective or have a good cost:benefit ratio. This review demonstrates that pharmacists can contribute to substantial healthcare savings across a variety of settings. However, there is a paucity of evidence in the literature highlighting the specific aspects of pharmacists' work which are the most effective and cost-effective. Future high-quality economic evaluations with robust methodologies and study design are required to investigate what pharmacist services have significant clinical benefits to patients and substantiate the greatest cost savings for healthcare budgets.