The collision occurred at approximately 8:55am and involved a car and a pedestrian.
The pedestrian, a female in her 80s, was fatally injured. Her body has since been removed to the morgue at University Hospital Limerick where a post mortem examination is due to take place.
There were no other injuries reported.
The L8050 road at Knockaveen remains closed and local diversions are in place.
A technical examination is being conducted by Forensic Collision Investigators.
Gardaí in Scarriff are appealing to anyone who may have witnessed this collision to contact them.
Any road users who were travelling in this area between 8:45am and 9:15am and may have camera footage (including dash-cam), are asked to make this available to Gardaí.
Anyone with any information is asked to contact Scarriff Garda Station on 061 922790, the Garda Confidential Line on 1800 666 111 or any Garda station.