Oak Park Co-operative Credit Society Limited - (1962-1974)
OLA Cheltenham Co-operative Credit Society Limited - (1960-1992)
Old Gold Credit Union Co-operative Limited - (1971- )
One Three Two Co-operative Credit Union Society Limited - (unknown-unknown)
Ophir County Council Employees Credit Union Limited - (1968-1974)
Orana Credit Union Limited - (1968-2008 )
Orange Base Hospital Staff Credit Union Limited - (1969-1973)
Orange Commonwealth Employees Credit Union Limited - (1968-1982)
Orange Credit Union Limited - (1964- )
Orion Credit Co-operative Society Limited - (1965-1984)
Orion Credit Union Limited - (1965-1996)
Otis Employees Credit Union Limited - (1970-1978)
Our Ladys Ringwood Co-operative Credit Society Limited - (1960-1985)
Outboard Marine Employees Credit Union Limited - (1972-1973)
Outlook Credit Union Co-operative Limited - (1972-1998)
Ovens Credit Co-operative Limited - (1964-1970)
Over 50s Credit Co-operative Limited - (unknown-1990)
Oxley Mutual Credit Union Limited - (1970-1988)