Onslow County, NC has a population of 183,753 people with a median age of 26.1 and a median household income of $46,335. Between 2014 and 2015 the population of Onslow County, NC grew from 182,921 to 183,753, a 0.45% increase and its median household income grew from $46,141 to $46,335, a 0.42% increase. The population of Onslow County, NC is 67.3% White, 14.8% Black, and 11.6% Hispanic.