Miller Place is a hamlet and census-designated place in the Town of Brookhaven, Suffolk County, New York, United States. Despite preserving much of its historic identity, changes in the 20th century have transitioned the hamlet into a desirable and densely populated suburban area. The population was 11,723 at the 2020 census. Miller Place and Mount Sinai are historically linked, with residents sharing such institutions as the Mount Sinai Congregational Church, located on the hamlet's border.