William Glasser (May 11, 1925 – August 23, 2013) was an American psychiatrist.
Glasser was the developer of reality therapy and choice theory. His ideas, which focus on personal choice, personal responsibility and personal transformation, are considered controversial by mainstream psychiatrists, who focus instead on classifying psychiatric syndromes, and who often prescribe psychotropic medications to treat mental disorders. Glasser was also notable for applying his theories to broader social issues, such as education, management, and marriage, to name a few. Glasser notably deviated from conventional psychiatrists by warning the general public about the potential detriments caused by the profession of psychiatry in its traditional form because of the common goal to diagnose a patient with a mental illness and prescribe medications to treat the particular illness when, in fact, the patient may simply be acting out of unhappiness, not a brain disorder. Glasser advocated the consideration of mental health as a public health issue.