Rapperswil-Jona is a municipality in the Wahlkreis of See-Gaster in the canton of St. Gallen in Switzerland.
Besides Rapperswil and Jona, which were separate municipalities until 2006, the municipality includes Bollingen, Busskirch, Curtiberg, Kempraten-Lenggis, Wagen, and Wurmsbach.
The official language of Rapperswil is German, but the main spoken language is the local variant of the Alemannic Swiss German dialect.