The regulatory approval standards for biosimilar products are distinct from those for generic chemically-synthesized (small molecule) medicines, which must be identical to the reference listed drug. In contrast to generic medicines, biosimilars are “highly similar” but not identical to the approved biologic product (reference product). The European Union (EU) served as the pioneer for establishing the regulatory framework for the approval of biosimilars following the enactment of legislation in 2003/2004 which empowered the European Medicines Agency (EMA) to approve biosimilar products. Subsequent to the regulatory guidance established by the EMA, guidelines for the approval of biosimilars have been developed in several key regions around the world such as Canada and Japan, as well as the World Health Organization (WHO). This presentation will review the history and development of the regulatory standards for the approval of biosimilars established by various regions and the WHO. The similarities as well as some of the key differences between the regional guidelines will also be reviewed.