The median annual wage for Private Detectives and Investigators in Illinois is $73,070 (May 2024 BLS OES). The mean (average) is $71,380.
Pay spans roughly $40,710 at the 10th percentile to $98,800 at the 90th, so experience and specialisation move this figure a lot. At the median that is about $35.13 per hour. An estimated 1,770 people work as private detectives and investigators in Illinois.
| Median (annual) | $73,070 |
| Mean (annual) | $71,380 |
| Median (hourly) | $35.13 |
| 10th percentile | $40,710 |
| 90th percentile | $98,800 |
| Employment | 1,770 |
Updated 2026-07-23.
Source: BLS OES May 2024 — bls.gov/oes. Checked 2026-07-23.