Occupational therapy (OT) is a healthcare profession. It involves the use of assessment and intervention to develop, recover, or maintain the meaningful activities, or occupations, of individuals, groups, or communities. The field of OT consists of health care practitioners trained and educated to improve mental and physical performance. Occupational therapists specialize in teaching, educating, and supporting participation in any activity that occupies an individual's time. It is an independent health profession sometimes categorized as an allied health profession and consists of occupational therapists (OTs) and occupational therapy assistants (OTAs). While OTs and OTAs have different roles, they both work with people who want to improve their mental and or physical health, disabilities, injuries, or impairments.

The American Occupational Therapy Association defines an occupational therapist as someone who "helps people across their lifespan participate in the things they want and/or need to do through the therapeutic use of everyday activities (occupations)". Definitions by professional occupational therapy organizations outside North America are similar in content.

Common interventions include:

• Helping children with disabilities to participate in school and social situations (independent mobility is often a central concern)
• Training in assistive device technology, meaningful and purposeful activities, and life skills.
• Physical injury rehabilitation
• Mental dysfunction rehabilitation
• Support of individuals across the age spectrum experiencing physical and cognitive changes
• Assessing ergonomics and assistive seating options to maximize independent function, while alleviating the risk of pressure injury
• Education in the disease and rehabilitation process
• Advocating for patient health

Typically, occupational therapists are university-educated professionals and must pass a licensing exam to practice. Currently, entry level occupational therapists must have a masters degree while certified occupational therapy assistants require a two year associates degree to practice in the United States. Individuals must pass a national board certification and apply for a state license in most states. Occupational therapists often work closely with professionals in physical therapy, speech–language pathology, audiology, nursing, nutrition, social work, psychology, medicine, and assistive technology.