Many Ontario cenotaphs used initials instead of given names. An excellent site with full names and details is the Commonwealth War Graves Commission
contact John Allan if you are willing to transcribe a cenotaph or other war memorial for OGSPI
OAK
OAKE
OBEMA
OBRIAN
OBRIEN
OBRIGHT
OCALLAGHAN
OCONNOR
ODELL
ODONAGHUE
ODONOGHUE
ODRISCOLL
ODROWSKI
OFARRELL
OFFER
OGRADY
OHARA
OHARE
OHERON
OHLMAN
OKANE
OKE
OLAN
OLAVESON
OLEARY
OLIMER
OLINK
OLIVER
OLIVIER
OLMSTED
OLSEN
OMAN
ONE
ONEIL
ONEILL
ONUSKI
ONYETT
ORAM
ORCHARD
OREILLY
ORFORD
OROK
ORRES
ORSER
ORTON
ORVILLE
ORVIS
OSAWOMIK
OSBORNE
OSLUND
OSSER
OSTRAM
OSTROM
OSTRUM
OTOOLE
OTTO
OUELLET
OUELLETTE
OUTRAM
OWEN
OWENS
OWNES
OXLEY
OYD