This collision happened yesterday afternoon on the Dublin Road in Longtown North in Clane.
It's understood the cyclist was hit by a passing vehicle that failed to remain at the scene
He was taken to Naas General Hospital where his injuries aren't thought to be life threatening.
Anyone who may have witnessed the crash or anyone with camera footage (including dash cam) is being asked to come forward.
People can contact Naas Garda Station or the Garda Confidential Line.