The alarm was raised by members of the public who spotted the woman in the River Corrib being swept out to sea.
They alerted the emergency services and a 'blanket' callout was made to the lifeboat, Garda, Irish Coast Guard, Galway Fire Brigade and the ambulance service at around 11.41pm.
Galway RNLI launched within minutes with helm Shane Folan and crew Dan King, Emma Hennessy and David Badger, and the woman was quickly located near waters at the Galway Enterprise Park at Galway Docks.
She was taken on board the lifeboat and brought ashore where she was transferred to a waiting ambulance and taken to University Hosptial Galway.
Galway RNLI shore crewmember John Byrne said: "The new emergency service plan for river rescues worked very well with all rescue services on the scene very quickly."
The rescue came a day after Clifden RNLI aided two lobster fishermen yesterday after their boat got into difficulty on the Connemara coastline.
At approximately 10.30am on Tuesday 5 May, Clifden RNLI's volunteer lifeboat crew was requested to launch by the Irish Coast Guard and go to the aid of two lobster fishermen in difficulty off the Aughrus peninsula.
Having experienced engine failure, the boat was drifting dangerously close to the rocks when its crew raised the alarm.
The Atlantic 85 inshore lifeboat Benjamin Downing Fairbridge was launched and was on the scene within 10 minutes of leaving shore.
Lifeboat helm Bernard Whelan and volunteer crew members Kenneth Flaherty, Joe Acton and Owen Hayes then towed the two fishermen in their boat back to Rossadillisk pier in Cleggan.
Speaking following the callout, Clifden RNLI lifeboat press officer Catherine Pryce said: "The crew responded rapidly and were delighted to be able to assist the fishermen."