Thiells, known as Thiell's Corner in the 1850s, is a hamlet and census-designated place (CDP) in the town of Haverstraw, Rockland County, New York, United States. It is located north of Mount Ivy, east of Pomona, south of Tomkins Cove, and west of Garnerville. The population was 5,032 as of the 2010 census.
During the American Revolution, Thiells was known as Haverstraw Forge, where General "Mad" Anthony Wayne, leading 1,350 Continental Army troops, was able to watch the area of Stony Point.
Thiells is located at 41°12′27″N 74°0′25″W (41.207392, −74.006829).
According to the United States Census Bureau, the CDP has a total area of 1.9 square miles (4.9 km2), of which 1.9 square miles (4.9 km2) is land and 0.53% is water.
Thiells is located on U.S. Route 202 between the Palisades Interstate Parkway and U.S. Route 9W and is west of the Hudson River.
As of the census of 2000, there were 4,758 people, 1,503 households, and 1,300 families residing in the CDP. The population density was 2,562.2 per square mile (987.7/km2). There were 1,512 housing units at an average density of 814.2/sq mi (313.9/km2). The racial makeup of the CDP was 88.10% White, 3.89% African American, 0.23% Native American, 2.82% Asian, 3.47% from other races, and 1.49% from two or more races. Hispanic or Latino of any race were 12.65% of the population.
There were 1,503 households, out of which 38.0% had children under the age of 18 living with them, 73.9% were married couples living together, 9.5% had a female householder with no husband present, and 13.5% were non-families.