The work involved repointing and replacing missing brickwork and removing vegetation from the lock chambers.
The locks date back to the 18th century and are grade II Listed. The six mile long Ashton Canal was originally built in 1792 to serve the coal industry around Oldham, Ashton and Hyde and in particular to compete with the Worsley mines.
David Baldacchino, from the Canal & River Trust, said: “A lock holds more than 50,000 gallons of water, the equivalent of over 400,000 pints of beer! Every single lock is unique and we use the same techniques to repair the brickwork as was used when they were built more than 200 years ago. The work we have done here will make sure these amazing structures continue to work for many years to come.”