- Oak
- Oath
- Obadiah
- Obal
- Obed
- Obededom
- Obil
- Oblation
- Oboth
- Ochran
- Oded
- Odomera
- Offerings
- Og
- Ohad
- Ohel
- Oholah
- Oholiab
- Oholibah
- Oholibamah
- Oil
- Oil Tree
- Ointment
- Old Testament
- Olive
- Olives, Mount of, and Olivet
- Olivet
- Olympas
- Omar
- Omega
- Omer
- Omri
- On 1
- On 2
- Onam
- Onan
- Onesimus
- Onesiphorus
- Onias
- Onion
- Ono
- Onycha
- Onyx
- Ophel
- Ophir
- Ophni
- Ophra
- Orator
- Orchard
- Oreb
- Oren
- Organ
- Orion
- Ornaments
- Ornan
- Orpah
- Orthosia
- Osnapper
- Ospray
- Ossifrage
- Ostrich
- Othni
- Othniel
- Oven
- Owl
- Ox
- Oxgoad
- Ozem
- Ozias
- Ozni
Edited by Frank W. Olive