She was part of the German team at FIFA Women's World Cup 2015. She scored a hat-trick in Germany's opening game against Ivory Coast on 7 June 2015, and would lead the tournament with six goals, scoring twice against Sweden in a 4-1 victory in the Round of 16, along with a penalty kick goal against France in the quarterfinals. However, she went on to miss a vital penalty kick versus the United States in the semifinals as Germany was eliminated. While Carli Lloyd scored three goals in the final to match Šašić's six and both had one assist, the tiebreaker regarding lesser playtime eventually gave Šašić the Golden Boot as the tournament top scorer. She subsequently announced her retirement from football on 17 July 2015.