Wendell Johnson (April 16, 1906 – August 29, 1965) was an American psychologist, author and was a proponent of general semantics (or GS). His life work contributed greatly to speech–language pathology, particularly in understanding the area of stuttering, as Johnson himself stuttered. The Wendell Johnson Speech and Hearing Center at University of Iowa is named after him. Aside from his contributions to stuttering, he posthumously became known for his controversial experiment nicknamed the "Monster Study".

Wendell Andrew Leroy Johnson was born April 16, 1906 in Roxbury, Kansas as the youngest child to Swedish immigrants Andrew and Mary Johnson. His family lived on a farm.

Johnson began to stutter when he was around the age of five or six.^{[citation needed]} He requested to be sent to schools to fix his stutter and was willing to try anything to cure it, but it proved to be lifelong.

Johnson was president of his high school class, captain of the football, baseball, and basketball teams, and valedictorian. He spent 2 years at a local college before moving to Iowa City, Iowa, to attend the University of Iowa. He chose this school due to their renowned Speech Clinic in hopes to have his stutter cured.

Considered one of the earliest and most influential speech pathologists in the field, Johnson spent most of his life trying to find the cause and cure for stuttering – through teaching, research, scholarly and other writing, lecturing, supervision of graduate students, and persuading K-12 schools, the Veterans Administration and other institutions of the need for speech pathologists. He played a major role in the creation of the American Speech and Hearing Association.

He was the first and most influential to introduce General Semantics into Speech Pathology, particularly stuttering and believed that "Stuttering often begins, not in the child's mouth, but in the parent's ear." He posited that when children who experience disfluent moments are told that they stutter - typically by well-meaning parents or therapists - it contributes and is a driving factor for why stuttering continues.

Patricia Zebrowski, University of Iowa assistant professor of speech pathology and audiology, notes, "The body of data that resulted from Johnson's work on children who stutter and their parents is still the largest collection of scientific information on the subject of stuttering onset. Although new work has determined that children who stutter are doing something different in their speech production than non-stutterers, Johnson was the first to talk about the importance of a stutterer's thoughts, attitudes, beliefs, and feelings. We still don't know what causes stuttering, but the 'Iowa' way of approaching study and treatment is still heavily influenced by Johnson, but with an added emphasis on speech production."

In 1930 Johnson published the book Because I Stutter, based on his master's thesis, which describes his struggles with stuttering from an autobiographical perspective.