The majority of the population of Aceh Tenggara Regency in 2023 is of working age.

The majority of the population in this region, or about 61.48%, are of productive age, namely 15-59 years old, totaling 142,220. According to a 2023 publication by the Central Bureau of Statistics (BPS), the number reached 142,220. The remaining population consists of those aged 0-14 years (children) at approximately 30.79% and 7.73% are the elderly group aged over 60 years.

The population of Aceh Tenggara Regency was recorded at 231,330 in 2023. Over the past 18 years, the population has continuously increased. Compared to the previous five years, the Compound Annual Growth Rate (CAGR) of this region is recorded as higher. The growth over the last five years was recorded at 2.1%.

In nominal terms, compared to other areas in Aceh Province, this district/city ranks ninth; while by island, it ranks 96th.

The following is the population by age in Aceh Tenggara Regency as of December 2023, sourced from a publication by the Central Bureau of Statistics (BPS):

* Age 0-4 years: 21,610 (9.34%)
* Age 5-9 years: 24,590 (10.63%)
* Age 10-14 years: 25,030 (10.82%)
* Age 15-19 years: 21,110 (9.13%)

* Age 20-24 years: 20,580 (8.89%)
* Age 25-29 years: 18,820 (8.13%)
* Age 30-34 years: 16,740 (7.24%)
* Age 35-39 years: 16,050 (6.94%)
* Age 40-44 years: 15,350 (6.64%)
* Age 45-49 years: 13,430 (5.81%)
* Age 50-54 years: 11,340 (4.9%)
* Age 55-59 years: 8,800 (3.8%)
* Age 60-64 years: 6,730 (2.91%)
* Age 65-69 years: 4,740 (2.05%)
* Age 70-74 years: 2,830 (1.22%)
* Age 75 years and over: 3,580 (1.55%)