Sopron (German: Ödenburg, Slovak: Šopron) was an administrative county (comitatus) of the Kingdom of Hungary.

Sopron county shared borders with the Austrian land Lower Austria and the Hungarian counties Moson, Győr, Veszprém and Vas.

The Sopron comitatus arose as one of the first comitati of the Kingdom of Hungary.

In 1921, it was decided by referendum that the city of Sopron and eight surrounding settlements would join Hungary instead of Austria.

In 1900, the county had a population of 279,796 people and was composed of the following linguistic communities:[1] Total: According to the census of 1900, the county was composed of the following religious communities:[2] Total: In 1910, the county had a population of 283,510 people and was composed of the following linguistic communities:[3] Total: According to the census of 1910, the county was composed of the following religious communities:[4] Total: In the early 20th century, the subdivisions of Sopron county were: Eisenstadt, Mattersburg, Rust and Oberpullendorf are now in Austria.