Alsó-Fehér was an administrative county (comitatus) of the Kingdom of Hungary.

The latest capital of the county was Nagyenyed (present-day Aiud).

In 1920, the Treaty of Trianon assigned the territory of the county to Romania.

Its territory lies in the present Romanian counties of Alba, Sibiu (the south-east) and Mureș (a small northeastern part).

In the early 20th century, the subdivisions of Alsó-Fehér county were: