Cedar Knolls is an unincorporated community located within Hanover Township in Morris County, in the U.S. state of New Jersey. It is part of Hanover Township along with Whippany.

It was first listed as a CDP in the 2020 census with a population of 4,082.

Cedar Knolls is in eastern Morris County, in the western part of Hanover Township. It is bordered to the east by Whippany, to the south by Morris Township, and partially to the west by the borough of Morris Plains. Interstate 287 forms the eastern border of Cedar Knolls and leads southwest 3 miles (5 km) to Morristown, the county seat, and northeast the same distance to Parsippany.

According to the U.S. Census Bureau, the Cedar Knolls CDP has an area of 2.09 square miles (5.41 km), of which 2.06 square miles (5.34 km) are land and 0.03 square miles (0.08 km), or 1.58%, are water. The Whippany River flows through the southeast part of the community and is part of the Passaic River watershed.

Historical population

Census	Pop.	Note	%±
2020	4,082		—
U.S. Decennial Census 2020

Cedar Knolls first appeared as a census designated place in the 2020 U.S. Census.

Cedar Knolls CDP, New Jersey – Racial and ethnic composition
Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.

Race / Ethnicity (NH = Non-Hispanic)	Pop 2020	% 2020
White alone (NH)	2,803	68.67%
Black or African American alone (NH)	192	4.70%
Native American or Alaska Native alone (NH)	3	0.07%
Asian alone (NH)	591	14.48%
Pacific Islander alone (NH)	2	0.05%
Other race alone (NH)	9	0.22%
Mixed race or Multiracial (NH)	124	3.04%
Hispanic or Latino (any race)	358	8.77%
Total	4,082	100.00%