DeKalb County is located in northern Illinois, with the city of DeKalb serving as the central hub. Northern Illinois University is based in DeKalb, bringing a strong educational and cultural presence to the county, while Sycamore serves as the county seat.

Agriculture remains an important part of DeKalb County, with expansive cornfields surrounding many of its communities. Wind turbines have also become a familiar sight across the landscape. Today, the county combines high-tech jobs and agriculture, creating a diverse local economy.

DeKalb County is well known for its connection to barbed wire, which was invented in the area. The historic Egyptian Theatre remains a local treasure and continues to host shows throughout the year. In the southwest, Shabbona Lake State Park offers opportunities for outdoor recreation and adds another highlight to the county.