Monoclonal antibodies have become a groundbreaking way to treat a wide array of diseases. Multiple diseases such as autoimmune diseases, cancer, metabolic syndrome, and infectious diseases can now be treated with monoclonal antibodies. Therapeutic monoclonal antibodies are widely used to treat blood disorders, auto-immune diseases and cancer. Bi-specific and multi-specific antibodies are among the innovative platforms that have expanded the use of monoclonal antibody therapeutics, making it possible to target multiple pathways or antigens simultaneously. Engineered monoclonal antibodies that have enhanced effector functions or extended half-lives have increased the effectiveness of treatment and improved patient outcomes. Companion diagnostics, developed as part of personalized medicine, help identify patients who are most likely to benefit from monoclonal antibody therapies.