Ellis was born in 1913 in Pittsburgh and raised in New York City. He had a difficult childhood due to family strife and health issues, which led him to focus on problem-solving through reading. In his early life, he aspired to be a novelist but was unable to get published. He then pursued psychoanalysis but grew dissatisfied with its limitations. He developed Rational Emotive Behavior Therapy (REBT), which argues that irrational beliefs cause emotional disturbances and that disputing these beliefs can resolve problems. REBT became popular through his many books and workshops. Ellis spent his career developing and promoting REBT until his death in 2007.