This chapter on regulatory considerations for antibody-drug conjugates (ADCs) in oncology highlights the unique and complex regulatory landscape required for their development, given their dual nature as biologics and small-molecule drugs. It provides an overview of key regulatory processes, including chemistry, manufacturing, and controls (CMC), where standards for antibodies and cytotoxic linkers must meet distinct regulatory expectations. The chapter also covers the organization of applications in eCTD format, meeting types with Food and Drug Administration (FDA), and key considerations for a successful regulatory application. Regulatory pathways, such as fast track and breakthrough therapy, are discussed as options to expedite ADC development, and detailed CMC requirements for various product components are emphasized to ensure patient safety and treatment efficacy through each development phase.