Speech therapy is the corrective or rehabilitative treatment of physical and/or cognitive deficits/disorders resulting in difficulty with verbal communication. This includes both speech (articulation, intonation, rate, intensity) and language (phonology, morphology, syntax, semantics, pragmatics, both receptive and expressive language, including reading and writing). Depending on the nature and severity of the disorder, common treatments may range from physical strengthening exercises, instructive or repetitive practice and drilling, to the use of audio-visual aids.

Speech and language therapists (SLTs) or speech-language pathologists (SLPs) provide a wide range of services for all ages, in early intervention (ages 0-3 years old), preschool, primary and secondary schooling, home care, and hospitals, rehabilitation centers, and nursing homes. Professionals often work with stroke victims, individuals with Asperger's syndrome or speech disorders (e.g. lisps, stammers), and with the deaf and hearing impaired. SLPs also provide services for individuals with dysphagia (difficulty swallowing).

See also: therapy, chorditis, logopedics, speech pathology, Phoniatrics, oral myology, Augmentative and Alternative Communication, Blissymbols