Shortly after 8pm, a passer-by noticed a female surfer in difficulty off Tullan Strand in Bundoran and immediately dialled 999.
Moments later the lifeboat crew were paged and within four minutes the Atlantic 85 lifeboat was launched from the pier, arriving on scene in under three minutes.
The crew brought the surfer and her surfboard on to the lifeboat and performed a quick medical check finding she was shaken but uninjured. The crew then returned to the station.
Speaking after their return, lifeboat helm Brian Gillespie said: "We are thankful to the member of the public who did the right thing by calling the coastguard.
"Darkness was beginning to fall and had it been any later the situation may have turned more dangerous. Thankfully the surfer is OK.
"As the weather is getting better, we want people to enjoy themselves but we would urge water users to exercise common sense and heed basic water safety principles.”