Dunkellin Bridge at Roveagh will be undergoing three months of repair works this summer after collapsing last year.
The South Galway bridge, which dates back to the 19th century partially collapsed last September.
The county council has made an order closing the Kilcornan Wood road at Dunkellin Bridge from Friday, May 31 until Friday, August 30.
The closure is for the dual purpose of carrying out bridge repair works and a flood relief scheme in the area.
Funding was secured in February from the Department of Transport to protect what remains of the historic structure while the collapsed section is going to be placed at the same time.
Remedial works are to be carried on the section that remains standing to ensure there is no future collapse, and new single span bridge will be constructed in the place of the collapsed section.
Councillor Joe Byrne has said that the single span design of the replacement was decided to ensure that that it wouldn’t require planning permission from An Bord Pleanála which would slow the project down.
Galway county council has been advising people who have had their travel disrupted in the area to divert via Kilcolgan.
