Around 225,000 fans watched the band perform a trio of concerts, and the shows are said to have generated £12.5m on tickets, £4m on food, drinks and merchandise on-site and £6.5m off-site on travel, food, drinks and accommodation.
Dr Alexander Roy, head of research at Manchester's economic think tank New Economy, said that the second coming of the Stone Roses "provided a boost to the economy that Manchester has been waiting for." and "showcased Manchester music to a new generation."
Councillor Pat Karney, city centre spokesman for Manchester council, said: "It has been like resurrection city, with visitors pouring into Manchester from all over Britain and Europe.
"It was one of the best economic weekends we've seen this year. Hotels, apartments, bars and restaurants have seen full houses. Every taxi driver became a Stone Roses fan overnight as they started making a fortune from the concerts.
"I'm not surprised it has provided a multi-million pound boost for Manchester. The band did Manchester proud and we are very proud of them."