He is being held at a garda station in the eastern region.
A man in his 20s has been arrested in connection with the assault of a woman in Newbridge.
The woman was found unresponsive at St Conleth's car park on the main street in the town on Wednesday morning.
The woman, who is aged in her 20s, was seriously injured and is continuing to receive treatment at Tallaght hospital.
Kfm understands that she had been stabbed.
The man is being held at a garda station in the eastern region.
Gardaí are continuing their appeal for information and are asking that anyone who was in the area between 11pm on Tuesday night and 8.15am on Wednesday morning to contact them.
Anyone with information is asked to contact Newbridge Garda Station on 045-440180, the Garda Confidential Line on 1800 666 111 or any garda station.

€1.2m Approved For Zipline And High Ropes Adventure Centre At Donadea
Fury After Sallins Sunshine Club Misses Out On Funding As Other Counties Get Millions
Christmas Appeal To Adopt Dogs As Euthanasia Figures Rise
Speed Enforcement To Increase In Kildare With 21 New Camera Zones To Be Rolled Out In January
Over 400 Motorists Caught Speeding So Far Today, Including A Driver In Kilcock
Transport Minister In Discussions With Irish Rail About Extending Late-Night Trains Beyond Christmas
Bus Shelters Treated As Luxury Rather Than Standard, With 500 Kildare Bus Stops In Need Of Upgrades
Recruitment Announcements Don’t Add Up As Garda Numbers Stagnant In Kildare South, Says Local TD