Methods, compositions and uses are provided for bispecific antibodies comprising one or more unnatural amino acids. The bispecific antibodies may bind to two or more different receptors, co-receptors, antigens, or cell markers on one or more cells. The bispecific antibodies may be used to treat a disease or condition (e.g., cancer, autoimmune disease, pathogenic infection, inflammatory disease). The bispecific antibodies may be used to modulate (e.g., stimulate or suppress) an immune response.