The land which is now Elmar Park was once a large farm which was built in the 1850s and owned by the Horning family. The name Elmar was taken from the names of two women who lived on the farm during the 1850's, Elsie and Marlene Horning, and was used as the registered name for the farm.
The property was acquired in 1989 through parkland dedication and was graded in 1990. The Barnstown Neighbourhood Park Association was formed to raise funds for the development of the site and to work on the park's design. Additional funds were provided by the City, and $1,000 was contributed by the Mountainview Residents for the Recreation of Hamilton.
Upon the suggestion of the neighbourhood park committee, the name Elmar was given to the park in 1991.