The proposal would see traffic banned from the area outside Trinity and the Bank of Ireland on Dame Street and replaced with pedestrian zone.
The repaving of Grafton Street -- due to begin early next year -- has cast a fresh spotlight on car-free proposals in the area.
Grafton Street was pedestrianised in the 1980s and is now the country's premier shopping thoroughfare.
Labour councillor Dermot Lacey has urged Dublin City Council's traffic planners to "take the bull by the horns" and come up with a plan for a plaza at College Green.
"It's not rocket science. It's very easily done," the former Lord Mayor said today.
He said traffic diversions would allow the plan to be implemented, without unduly inconveniencing motorists.
Southbound cars and buses coming across O'Connell Bridge could be diverted left from D'Olier Street on to Townsend Street, instead of passing in front of the main entrance to Trinity, he suggested.
Reports emerged last year that the State may be preparing to buy Bank of Ireland's historic College Green building as part of a redevelopment of the area.
Mr Lacey believes the bank should cooperate with any such proposal, in light of the taxpayer money it has already received.
Fianna Fail councillor Mary Fitzpatrick said recently the built environment at College Green lends itself to a "big public plaza".
Traffic through the zone has already been reduced, giving buses and taxis priority.
Councillors have also supported a proposal by traders to pedestrianise a number of Dublin city's busiest streets.