Mr Keir, 99, is the second person to receive the prestigious title which was given in recognition of his achievements during his life and career, including the part he played in the Second World War.
Following the unanimous vote by councillors, Mr Keir was presented with a certificate bearing his new title of Honorary Freeman of Derbyshire by Civic Chairman Councillor Tony Kemp at a special meeting on Wednesday.
His name will also be added to the roll of honour kept by the Monitoring Officer.