At one point it seemed that the hamlet of Deer Park would never have a public library, as a proposition to construct a library building was voted down three times between 1957 and 1962. In the interim, Deer Park was served by a bookmobile sponsored by the Suffolk Cooperative Library System. In May of 1963 another committee suggested the idea to the school board to build a library. A fourth proposition was put to a vote on June 30, 1964. It was narrowly approved, 730 to 679. Deer Park Public Library officially opened its doors on August 1, 1966, with Mrs. Marianne Woolfe as Director.
Today the Deer Park Public Library serves the nearly 28,000 residents of the Deer Park community.