Monoclonal antibodies have become one of the most clinically successful therapeutic agents against a range of diseases, including cancer, autoimmune diseases, and most recently SARS-CoV-2. Although engagement of the antigen via the variable Fab portion of the antibody is essential, the function of many therapeutic antibodies also depends, to varying degrees, on the hinge and Fc portion of the antibody and the interaction with receptors on effector cells. Antibody subclass choice is crucial for optimal function and safety of therapeutic antibodies because the functional profile of each subclass differs greatly. Targeted modification of the Fc region and its associated glycan is also a potent and effective approach to tailor the therapeutic function of antibodies for the disease of choice, by improving or reducing the immune cell-associated effector functions and altering the circulating half-life of the antibody. One advantage of these Fc modifications is that they can be easily transferred to antibodies of any target, and so development of novel antibodies against a wide range of diseases have benefited from the modifications previously developed and characterized for different indications.