Biosimilar medicines have become increasingly important in contemporary pharmaceutical care because they can expand access to complex biological therapies while potentially reducing treatment expenditure. Unlike conventional generic medicines, biosimilars are not molecularly identical copies of their reference biological products because biological medicines are inherently complex and are manufactured using living systems. Consequently, their development and clinical use require a regulatory framework based on comprehensive analytical, functional, non-clinical, and, where appropriate, clinical comparability. The ethical governance of biosimilars therefore extends beyond demonstration of pharmaceutical quality and clinical similarity to encompass patient safety, equitable access, informed decision-making, interchangeability, pharmacovigilance, professional accountability, and responsible allocation of healthcare resources. This review examines biosimilar governance from a pharmacy ethics perspective, with particular emphasis on India and the United Kingdom. The Indian framework has evolved through the Guidelines on Similar Biologics issued by the Department of Biotechnology and the Central Drugs Standard Control Organization, whereas the United Kingdom regulates biosimilars through the Medicines and Healthcare products Regulatory Agency and associated national healthcare policies. Both systems emphasize quality, safety, efficacy, traceability, and post-marketing surveillance, but differences exist in regulatory organization, interchangeability, pharmacy-level substitution, patient involvement in switching decisions, and implementation of pharmacovigilance. In the UK, an authorized biosimilar is considered interchangeable with its reference product from a regulatory perspective, while pharmacy-level substitution without prescriber involvement is not permitted. In India, regulatory approval establishes biosimilarity, but the practical framework for interchangeability and substitution remains less explicitly standardized across routine pharmacy practice. From an ethical perspective, responsible biosimilar governance requires balancing individual patient interests with the collective objective of improving access to affordable biological therapies. Pharmacists have important responsibilities in product identification, patient education, adverse-event reporting, medication safety, and communication regarding switching. A patient-centred approach should avoid both unjustified resistance to biosimilars and inappropriate substitution driven solely by cost. Greater regulatory harmonization, transparent pharmacovigilance, standardized product traceability, pharmacist education, and meaningful patient participation may strengthen ethical biosimilar implementation in India and the United Kingdom.