Eduard Einstein (28 July 1910 – 25 October 1965) was born in Zürich, Switzerland, the second son of physicist Albert Einstein from his first wife Mileva Marić. Albert Einstein and his family moved to Berlin in 1914. Shortly thereafter the parents separated, and Marić returned to Zürich, taking Eduard and his older brother Hans Albert with her. His father remarried in 1919 and in the 1930s emigrated to the United States under the threat of the German Nazi regime.

Eduard was a good student and had musical talent. After gymnasium, he started to study medicine to become a psychiatrist, but by the age of twenty, he was diagnosed with schizophrenia. He was institutionalized two years later for the first of several times. Biographers of his father have speculated that the drugs and "cures" of the time damaged rather than aided the young Einstein, but schizophrenia can be intractable. His brother Hans Albert Einstein believed that his memory and cognitive abilities were damaged by electroconvulsive therapy treatments.

After suffering a breakdown, Eduard had told his father that he hated him. Albert Einstein immigrated to the United States from Germany in 1933 after the rise of the Nazi German government and never saw his son again. The father and son, whom the father fondly referred to as "Tete" (for petit), corresponded regularly before and after Eduard became ill. Their correspondence continued after the father's immigration to the United States.

Eduard remained interested in music and art, wrote poetry, and was a Sigmund Freud enthusiast. He hung a picture of Freud on his bedroom wall.

His mother cared for him until she died in 1948. From then on Eduard lived most of the time at the psychiatric clinic Burghölzli in Zurich, where he died in 1965 of a stroke at age 55. He is buried at Hönggerberg Cemetery in Zurich.] Groups working to support research on mental illness have used the prominence of the Einstein family to help raise public awareness of schizophrenia.