Gardaí responded to reports of a man's body on Parnell Place at around midday and sealed off an area at the entrance to Merchant's Quay car park.
The man in his mid 30s is believed to be a user of homeless services in the city and may have been dead for a number of days before he was discovered.
Gardaí are trying to establish the circumstances of the incident and say the results of a post mortem will determine the course of their investigation.
