Glasser was born May 11, 1925, in Cleveland, Ohio, to Ben Glasser, a watch and clock repairman, and his wife Betty. He attended Case Western Reserve University in Cleveland, where in 1945 he earned his BS in chemical engineering. After a short career as an Engineer, Glasser returned in 1946 to Case Western, but instead, during his first semester, was drafted into the US Army and stationed at Dugway Proving Ground in Utah. He returned to Case Western in 1947, earning his MA in clinical psychology in 1949 and his MD in psychiatry in 1953. He completed his medical internship and psychiatric residency at UCLA and the Veterans Administration Hospital, respectively, and became board certified in 1961.
Glasser founded the Institute for Reality Therapy in 1967, which was renamed the Institute for Control Theory, Reality Therapy and Lead Management in 1994 and later the william Glasser Institute in 1996 in Chatsworth, CA. The institute is now located in Tempe, Arizona, and has branch institutes throughout the world.
By the 1970s Glasser called his body of work "Control Theory". By 1996, the theoretical structure evolved into a comprehensive body of work renamed "Choice Theory", mainly because of the confusion with perceptual control theory by william T. Powers, developed in the 1950s.
Glasser set up a private psychotherapy practice in Los Angeles, which he maintained until 1986.
In Nashville, USA, in July 2010, william Glasser Association International (WGAI) was established with an interim governing board charged with setting up the organization to coordinate worldwide activities and conferences, the first of which was in 2012 in Los Angeles. This board eventually became incorporated in California, USA under the new name of "William Glasser International" (WGI) and is the umbrella body recognised by william Glasser to represent his ideas around the world. The members of the WGI Board are elected by members.
Glasser died at his home in Los Angeles on August 23, 2013, in the company of his wife, Carleen, and others. Glasser's obituary reported the cause of death as respiratory failure stemming from pneumonia. The william Glasser Institute website referred to Glasser's death as "a massive shock to all", despite him having been "in poor health for some time".