This article lists notable underwater diver certification agencies. These include certification in cave diving, commercial diving, recreational diving, technical diving and freediving. Diver certification agencies are organisations which issue certification of competence in diving skills under their own name, and which train, assess, certify and register the instructors licensed to present courses following the standards for the certification they issue.

Recreational scuba diving certification agencies

Organisations which publish standards for competence in recreational scuba diving skills and knowledge, and issue certification for divers assessed as competent against these standards by affiliated schools or instructors:

Recreational certification organisations no longer operating

Technical diving certification agencies

Organisations which publish standards for competence in technical diving skills and knowledge, and issue certification for divers assessed as competent against these standards by affiliated schools or instructors:

Cave diving certification agencies

Organisations which publish standards for competence in cave diving skills and knowledge, and issue certification for divers assessed as competent against these standards by affiliated schools or instructors:

Freediving and snorkelling certification agencies

Organisations which publish standards for competence in freediving and snorkelling skills and knowledge, and issue certification for divers assessed as competent against these standards by affiliated schools or instructors:

Commercial diver training and registration authorities

Organisations which publish standards for competence in commercial diving skills and knowledge, and issue certification for divers assessed as competent against these standards by registered or affiliated schools: Organisations specifically certifying public safety divers:

Scientific diving certification agencies

Organisations which publish standards for competence in scientific diving skills and knowledge, and issue certification for divers assessed as competent against these standards by affiliated schools or instructors:

Other certification agencies for skills associated with diving

Dedicated diver first aid & rescue training

Maritime archaeology

Professional associations for diving instructors

International standards, accreditation and quality assurance organisations