Immune checkpoint inhibitors (ICIs) have transformed cancer care. Recently, atezolizumab gained its first global approval in a subcutaneous (SC) formulation by the UK medicines regulator, being notable as the first time an FDA- and/or European Medicines Agency (EMA)-approved ICI has been licensed via this administration route. Here, we discuss this approval, other SC ICIs in development, and the benefits and challenges of this administration route, including potential implications for patient care.