North Down Borough Council organised the event to mark the support given by reservists from across Northern Ireland to overseas operations.
The soldiers, mostly from 591 Independent Engineer Squadron RE (V), based in Bangor, formed outside Bangor Castle as a ceremony was held inside the council chamber.
After being inspected by the Mayor, Councillor Wesley Irvine, the soldiers paraded through the town before a formal reception at Bangor Castle.
Soldiers from 591 Independent Engineer Squadron have a long record of operational service and some of those on parade have just recently returned from Afganistan.
The Officer Commanding, Major Kevin Thomas, said it is not just an honour for the reserve engineers but is being accepted on behalf of all TA soldiers across NI who have served over the years - most recently in both Iraq and Afghanistan.
"These are men and women who have given their spare time, their talents and their enthusiasm often at cost to themselves and family, so that they can work for peace for all people," he said.
"It is a very fitting and appropriate gesture by North Down Borough Council on behalf of everyone in the community and we are exceptionally grateful."
Cllr Wesley Irvine added: "I have to say that I find the sheer dedication and commitment of the brave men and women of the Territorial Army to be quite inspiring.
"As Mayor of North Down, I am greatly honoured and proud to be in office on this momentous occasion when the Council has conferred the Freedome of the Borough on the men and women of the Territorial Army and specifically 591 Independent Engineer Squadron RE.
"It is, of course, a very special privilege for any Mayor to participate in a Freedom of the Borough ceremony since they occur so infrequently. Hence, today's occasion is a very special highlight coming as it does at the end of my year in office."