FREEDOM of the borough was formally bestowed on former Croydon North MP Malcolm Wicks at a special meeting of Croydon Council on Monday.
Mr Wicks, who died in September at the age of 65, is the first person to be granted the honour posthumously.
He had been an MP in Croydon for 20 years.
At the ceremony his widow Margaret told councillors: "Malcolm would have been very pleased and proud of this great honour that has been conferred on him today."
She said she and her children, Roger, Sarah and Caroline, had been very moved by the respect that had been shown to Mr Wicks by the council.
Proposing the honour, council leader Mike Fisher described Mr Wicks as "a truly great servant of the borough" and a pragmatic and sensible politician."
Councillor Fisher added: "He was always a champion of the underdog. Throughout his life he had been dedicated to helping others and serving his constituents."
Seconding the motion, Labour opposition leader Tony Newman praised Mr Wicks' support for the town.
He said: "After the riots last year Malcolm stood up and fought for his constituents like never before."
He added: "For a politician to be so respected both locally and nationally is rare but for a politician to be so loved and still so missed after 20 years in office is unparalleled."
