William James Morton (July 3, 1845 – March 26, 1920) was a United States physician, an authority in electrotherapeutics.

Settling in New York City, he became editor of the Journal of Nervous and Mental Disease.

As an authority in electrotherapeutics he won wide recognition, and by his mechanical device for establishing the "static induced current" of electricity – the "Morton current" of the scientific world – supplied a means for producing the x-ray, a service of great practical value to medicine and surgery.

Indicted in January 1912, in association with Julian Hawthorne and others, on a charge of fraudulent use of the mails in the promotion of bogus mining companies, conviction followed nearly a year after.

He was sentenced to 12 months' imprisonment, but was released in October 1913, pardoned by the president and reinstated in his profession.