| Name | Membership No. | Grade | Branch |
|---|---|---|---|
| Emmanuel Emeka Osegbo | SE 0397 | Member | Lagos |
| Anthony Ikeka Osemenam | SE 0090 | Fellow | Lagos |
| Festus Alfred Oseni | SE 0101 | Fellow | Lagos |
| Olalekan Semiu Oseni | SE 0718 | Member | – |
| Emmanuel Adeseye Oshinyemi | SE 0509 | Fellow | Lagos |
| Lawrence A. Osho | SE 0070 | Member | Lagos |
| Oluwole Oluseye Osho | SE 0097 | Member | Ibadan |
| O. Olawale Osibajo | SE 0651 | Fellow | Lagos |
| - Osibajo, Elijah | SE 0585 | Fellow | Lagos |
| Babatunde O.J Osibodu | SE 0379 | Member | Lagos |
| John Emiola Osibodu | SE 0039 | Fellow | Lagos |
| Dr. Kehinde Babajide, Gabriel Osifala | SE 0441 | Fellow | Lagos |
| Emmanuel Ade Osinyemi | SE 0236 | Fellow | Lagos |
| Okechukwu Emmanuel Ossai | SE 0419 | Fellow | Owerri |
| Dr. Sylvester O Osuji | SE 0666 | Member | Benin |
| Akinloye Joseph Osundolire | SE 0758 | Member | Lagos |
| Otuonye Chimezie Oti | SE 0212 | Member | – |
| Ajose Olaribigbe Otinwa | SE 0475 | Fellow | Lagos |
| Daniel John Otoyo | SE 0619 | Member | Uyo |
| Atilade Alaba Otunla | SE 0700 | Member | Ibadan |
| Dogun Nansak Ovie | SE 0764 | Member | Abuja |
| Magdalene Azuka Ovuewhorie | SE 0359 | Member | Lagos |
| Ololade Adisa Ow0Koniran | SE 0564 | Member | Lagos |
| Olumide Olatunji Owolabi | SE 0781 | Member | Lagos |
| Samson Tunde Owolabi | SE 0719 | Member | Lagos |