Officers are investigating the fatal road traffic collision, which occurred on the N81 in the townland of Poulaphuca at Blessington, at approximately 9.15pm.
A 33-year-old motorcyclist was fatally injured when he and a second motorcyclist collided with a jeep.
Emergency services were called but the man was pronounced dead at scene. His body was removed to Naas General Hospital where a post-mortem will take place.
The second male motorcyclist, a 49-year-old man, was seriously injured in the collision. He was rushed to Naas General Hospital where his condition is described as serious.
The driver of the jeep, a 61-year-old woman, was taken to Tallaght Hospital with minor injuries.
The scene has been preserved and Garda Forensic Collision Investigators will carry out an investigation of the area. Diversions are in place, Gardai said.
Gardaí are appealing for witnessess or anyone who was travelling on the N81 last night to contact them at Baltinglass Garda Station on 059 - 6482610, the Garda Confidential Line, 1800 666111 or any Garda Station.