The present disclosure provides antibodies that specifically bind to human OX40 receptor (OX40) and/or human GITR receptor (GITR), including multispecific antibodies that bind, e.g., to OX40 and GITR, and compositions comprising such antibodies. The antibodies disclosed herein modulate OX40 and/or GITR activity e.g., enhance, activate, induce, reduce, deactivate, or inhibit OX40 and/or GITR activity. The present disclosure also provides methods for treating disorders, such as cancer, autoimmune diseases or disorders, or inflammatory diseases or disorders, by administering an antibody that specifically binds to human OX40 and/or human GITR and modulates OX40 and/or GITR activity.