Speech-language pathology is a field of expertise practiced by a clinician known as a speech-language pathologist (SLP)^[1] or a speech and language therapist, both of whom may be known by the shortened description, speech therapist. SLP is considered a "related health profession" or "allied health profession" along with audiology, optometry, occupational therapy, rehabilitation psychology, physical therapy, behavior analysis and others.

SLPs specialize in the evaluation, diagnosis, and treatment of communication disorders (speech disorders and language disorders), cognitive-communication disorders, voice disorders, and swallowing disorders. SLPs also play an important role in the diagnosis and treatment of autism spectrum disorder (often in a team with pediatricians and psychologists).