- Oral science international
- Oral surgery
- Orbis litterarum
- Orbit
- Organic letters
- Organic process research & development
- Organised sound
- Organisms, diversity & evolution
- Organization studies
- Organizational psychology review
- Organizational research methods
- Organometallics
- Origins of life and evolution of the biosphere
- ORNAC journal
- Ornithological applications / American Ornithological Society
- Ornithology
- Orthodontics and craniofacial research
- Orthopaedic proceedings
- Orthopaedics and trauma
- Orthopedic clinics of North America
- Orthopedic nursing
- Orthopedics
- Oryx
- Osteoarthritis and cartilage
- Osteoporosis international
- OTJR : occupation, participation and health
- Otolaryngologic clinics of North America
- Otolaryngology case reports
- Otolaryngology--head and neck surgery
- Otology & neurotology
- Oxford journal of archaeology
- Pacific focus
- Pacific philosophical quarterly
- Pacific Rim international journal of nursing research
- Pacing and clinical electrophysiology : PACE
- Packaging technology and science
- Paediatric anaesthesia
- Paediatric and perinatal epidemiology
- Paediatric respiratory reviews
- Paediatrics & child health
- Paediatrics and child health
- Paediatrics and international child health
- Pain
- Pain medicine
- Pain practice
- Palaeontology
- Palaestra
- Paläontologische Zeitschrift
- Paleobiology
- Paleoceanography