The glider was found on the northern flank of the Chlein Seehorn on Thursday, Saint Gallen cantonal police said.
The plane was reported missing the day before after taking off from the Schänis aerodrome, west of Lake Walen (Walensee) in the canton of Saint Gallen, shortly before 12.15pm, police said in a news release.
The pilot was planning to compete in the Swiss junior gliding championships, according to the release.
After the aircraft failed to return to the Schänis airport, a major search was launched involving a Swiss Air Force Super Puma helicopter and the Rega emergency rescue service.
The search continued until 2am, with the air force helicopter using thermal imaging cameras,, according to a report from Der Landbote newspaper.
The search resumed on Thursday morning with four helicopters, the daily said.
Another pilot had seen the glider at around 3pm in the Sulzfluh/Saint Antönien area, north of Klosters, the last time anyone was in visual contact with the plane.
The cause of the crash was not immediately known.
The Swiss safety investigation authority (SUST) has launched an investigation into the incident.
“We are deeply saddened by this disaster,” Peter Schmid, a spokesman for the junior gliding championships organization is quoted as saying by the online version of Der Landbote.
The newspaper said pilots competing in the competition would decide on Friday morning whether to continue the championship.