Werdenberg (Wahlkreis) or Wahlkreis Werdenberg is a constituency in the canton of St. Gallen in Switzerland. The Wahlkreis (SFOS number 1724) was established on June 10, 2001. The Wahlkreis has its name by the municipality Grabs-Werdenberg.

Werdenberg Wahlkreis has a population of 39,993 (as of 31 December 2020). Of the foreign population, (as of 2000), 661 are from Germany, 908 are from Italy, 3,006 are from ex-Yugoslavia, 567 are from Austria, 390 are from Turkey, and 1,124 are from another country.