Julie Ertz played collegiate soccer with the Santa Clara University Broncos from 2010 to 2013. Following her collegiate career, Ertz was selected third overall by the Chicago Red Stars in the 2014 NWSL College Draft.
She first appeared for the United States national team during an international friendly against Scotland on February 9, 2013. She has since made more than 100 total appearances for the team. Ertz helped the United States win their titles at the 2015 and 2019 FIFA Women's World Cup. The United States went on to the World Cup final where she played every minute of all seven games of the tournament and was subsequently named to the FIFA Women's World Cup All-Star Team.
In 2017, Ertz was awarded U.S. Soccer Female Player of the Year. Ertz was again nominated for U.S. Soccer Female Player of the Year in 2018 and won the U.S. Soccer Female Player of the Year in 2019.