High Elms Manor is a grade II listed Georgian country house located near Garston in Hertfordshire, England. It was built in around 1812, and was originally known as "High Elms", but from the 1890s to 2010 it was called Garston Manor. In the post World War II years the house was a rehabilitation centre, but it later fell derelict. In the 1990s an American named Sheila O'Neill bought and restored it and it was used by her as a Montessori School until her death, and then subsequently by her daughters, who have now put it on the market.