The local branch of the Lions Club came up with the idea in 1943 of building a community hospital in Trenton. The Rotary Club joined the Lions Club in supporting the hospital project and they jointly purchased nine acres of pasture land for $1,000. The total cost of the hospital project was estimated at $275,000.
The first Board of Directors was formed in 1944. Construction began with a sod-turning on August 29, 1946. The first cornerstone was laid on October 15, 1947. The hospital was completed in 1951, with the Official Opening on February 25th of that year. The hospital was dedicated as a memorial to the town of Trenton's war dead, hence its name "Trenton Memorial Hospital".
Expansions took place in 1961 (two full wings and one partial wing added to the original building) and in 1969 (a two-storey addition to the east end of the hospital).
The hospital became known as "Quinte Health Care Trenton Memorial" upon the amalgamation of the hospitals in Bancroft, Belleville, Picton, and Trenton in November 1998.
Trenton Memorial underwent an extensive redevelopment project that was completed in 2006. It virtually doubled the size of the hospital with a 45,000 square foot wing which is modern, bright, climate-controlled, and barrier-free.