Brother Kevin was recognised for his free meals charity, which he has run for nearly 50 years.
He took the opportunity to express concern about a new drug crisis facing the capital and appealed to the Government to do something about the situation.
Giles received the award for his footballing career and for the John Giles Foundation, which tries to help young people through sport.
Dublin Lord Mayor Christy Burke recommended the two men for the honour.
He said: "I was asked how would I sum up both gentlemen, and I said: 'Well it's very simple, one prayed and the other played'."