Smithville Flats is a census-designated place and hamlet in the town of Smithville, Chenango County, New York, United States. The zipcode is 13841. Its population was 351 as of the 2010 census.

In the 2020 census, Smithville Flats had 303 people, 164 households, and 158 housing units. The racial demographics were 92.7% White, 1.3% African American, 0.6% Asian, 0.6% from some other race, and 4.6% from two or more races. The median age was 38.4 years old. 11.9% of the population were 65 or older, 9.3% of the population were between the ages of 65 to 74, 2.0% between the ages of 75 to 84, and 0.6% were 85 or older.

The median income of Smithville Flats was $55,938. Families had a median income of $69,063 and non-families had a median income of $29,135. The CDP had a poverty rate of 11.9%. Children had a poverty rate of 20%, adults had a poverty rate of 9.1%, and seniors had a poverty rate of 7.3%.

The ancestry of the CDP was 26.2% Irish, 13.4% American, 11.9% Welsh, 7.6% English, 6.7% German, 3.8% Dutch, 3.5% Italian, and 2.3% West Indian.

Historical population

Census	Pop.	Note	%±
2020	303		—
U.S. Decennial Census