George O'Malley was the son of Harold and Louise O'Malley. He went to medical school and became an intern at Seattle Grace Hospital. George failed his exam and was forced to retake his intern year. He took a follow-up exam a few months later and passed. Fellow resident Izzie Stevens was his best friend and for a brief time he was married to Callie Torres. He was kind-hearted, compassionate, loyal and had an excellent bedside manner.

After he joined the army to be a trauma surgeon, Richard gave him the last day in the hospital off to spend time with his family. On his way home, George jumped in front of a bus to save a woman's life. George died on the operating table.