Allendale is a city located in South Carolina. With a 2020 population of 2,973, it is the 89th largest city in South Carolina and the 6269th largest city in the United States. Allendale is currently declining at a rate of -0.10% annually and its population has decreased by -14.62% since the most recent census, which recorded a population of 3,482 in 2010. Allendale reached it's highest population of 4,410 in 1990. Spanning over 3 miles, Allendale has a population density of 898 people per square mile.
The average household income in Allendale is $26,655 with a poverty rate of 34.77%. The median rental costs in recent years comes to $616 per month, and the median house value is $36,700. The median age in Allendale is 35.8 years, 30.8 years for males, and 43.8 years for females. For every 100 females there are 83.3 males.