The Downstate Correctional Facility in Fishkill will close on Thursday after nearly 50 years in operation.
The state announced last November that Downstate, a maximum-security facility, was among six prisons statewide set to close.
More than 1,500 people worked at the facility, but the state had said there would not be any layoffs.
The facility’s 690 prisoners will be moved to other facilities that have vacant cells.
The state said the prisons are being closed because of a drop in the prison population.
The closing of the Fishkill facility was criticized by local officials who said it would have a financial impact on surrounding communities.