Bergdietikon is a municipality in the district of Baden in the canton of Aargau in Switzerland.

Following the Act of Mediation in 1803, the Canton of Baden was dismantled and the municipality of Dietikon was split.

Of the rest of the land, 16.8% is settled (buildings or roads) and the remainder (1.3%) is non-productive (rivers or lakes).

[4] The municipality is located in the Baden district on the southwest slope of the Heitersberg.

It consists of the farm settlements of Baltenswil, Schönenberg, Herrenberg, Bernold, Kindhausen and Gwinden.

The blazon of the municipal coat of arms is Argent an Oak Tree Vert eradicated and Coupeaux of the same.

[4] The age distribution, as of 2008[update], in Bergdietikon is; 189 children or 8.3% of the population are between 0 and 9 years old and 190 teenagers or 8.4% are between 10 and 19.

[11] From the 2000 census[update], 763 or 33.8% are Roman Catholic, while 1,109 or 49.2% belonged to the Swiss Reformed Church.