Martina Hingis is a citizen of Switzerland, but was born Czechoslovakia.
Czechoslovakia or Czecho-Slovakia [ ˌtʃɛkoʊsloʊˈvækiə , _ - kə - , _ - slə - , _ - ˈvɑː - ] ( Czech and Československo , Česko-Slovensko ) was a sovereign state in Central Europe that existed from October 1918 , when it declared its independence from the Austro-Hungarian Empire , until its peaceful dissolution into the Czech Republic and Slovakia on 1 January 1993 . Martina Hingis ( born 30 September 1980 ) is a Czechoslovak-born Swiss professional tennis player who spent a total of 209 weeks as the singles world No. 1 . The Swiss ( die Schweizer , les Suisses , gli Svizzeri , ils Svizzers ) are citizens of Switzerland .