Bad Zurzach (Swiss Standard German pronunciation: [baːd ˈtsʊrtsax] ^ⓘ) is a village and former municipality in the district of Zurzach in the canton of Aargau in Switzerland. It is the seat of the district. On 1 January 2022 the former municipalities of Bad Zurzach, Baldingen, Böbikon, Kaiserstuhl, Rekingen, Rietheim, Rümikon and Wislikofen merged into the new municipality of Zurzach.

Bad Zurzach was previously known as Zurzach; the population voting for the official name change in a referendum of 21 May 2006. Located on the Rhine, Bad Zurzach has a thermal water bath and an outdoor bathing facility. The old market town, the St. Verena convent church with its treasure, the Roman Catholic Church and the late Roman castle Tenedo on the Kirchlibuck hill are listed as heritage sites of national significance.

Bad Zurzach has an area, as of 2009^[update], of 6.52 square kilometers (2.52 sq mi). Of this area, 1.64 km² (0.63 sq mi) or 25.2% is used for agricultural purposes, while 2.78 km² (1.07 sq mi) or 42.6% is forested. Of the rest of the land, 1.82 km² (0.70 sq mi) or 27.9% is settled (buildings or roads), 0.28 km² (0.11 sq mi) or 4.3% is either rivers or lakes and 0.01 km² (2.5 acres) or 0.2% is unproductive land.

Of the built up area, industrial buildings made up 3.1% of the total area while housing and buildings made up 12.7% and transportation infrastructure made up 7.5%. while parks, green belts and sports fields made up 4.3%. Out of the forested land, 40.8% of the total land area is heavily forested and 1.8% is covered with orchards or small clusters of trees. Of the agricultural land, 15.3% is used for growing crops and 8.7% is pastures, while 1.1% is used for orchards or vine crops. All the water in the municipality is flowing water.

Across the river Rhein is the village of Rheinheim in the German state of Baden-Württemberg.

The blazon of the municipal coat of arms is Argent a Letter Z Sable.

Bad Zurzach has a population (as of December 2020^[update]) of 4,379. As of 2008^[update], 34.7% of the population are foreign nationals. Over the last 10 years (1997–2007) the population has changed at a rate of 4.2%. Most of the population (as of 2000^[update]) speaks German (82.9%), with Serbo-Croatian being second most common (3.3%) and Italian being third (3.2%).

As of 2008^[update], the gender distribution of the population was 49.9% male and 50.1% female. The population was made up of 1,274 Swiss men (31.6% of the population), and 736 (18.3%) non-Swiss men. There were 1,410 Swiss women (35.0%), and 610 (15.1%) non-Swiss women. In 2008^[update] there were 17 live births to Swiss citizens and 11 births to non-Swiss citizens, and in same time span there were 39 deaths of Swiss citizens and 7 non-Swiss citizen deaths. Ignoring immigration and emigration, the population of Swiss citizens decreased by 22 while the foreign population increased by 4. There were 2 Swiss men who emigrated from Switzerland to another country, 1 Swiss woman who emigrated from Switzerland to another country, 69 non-Swiss men who emigrated from Switzerland to another country and 40 non-Swiss women who emigrated from Switzerland to another country. The total Swiss population change in 2008 (from all sources) was a decrease of 39 and the non-Swiss population change was an increase of 66 people. This represents a population growth rate of 0.7%.