Ertz has represented the United States at one FIFA Women's World Cup tournament in 2015. At 23, she was the second youngest member of the team behind 22-year-old Morgan Brian. In the 59th minute of the team's semifinal match against Germany on June 30, Ertz pulled down Germany's Alexandra Popp inside the penalty box and was given a yellow card. Celia Sasic of Germany took the subsequent penalty kick but missed the net. The United States went on to win the match 2–0 to advance to the World Cup final. Ertz played every minute of all seven games of the World Cup and was subsequently named to the FIFA Women's World Cup All-Star Team.
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 that took place on January 17, 2014. She is currently in her third season with the Red Stars.
Born in Mesa, Arizona to Kristi and David Johnston, Julie was raised with her older sister Melanie Johnston. Both played club soccer for Arizona Arsenal Soccer Club, formally Gilbert Soccer Club, from 2000 to 2004. In need of a more challenging environment, the Johnston sisters switched to play for Sereno Soccer Club in Phoenix Julie played for the 92's and Melanie played for the 90's. Regarding Julie's switch to the team, Johnston stated that "it ended up being the best decision [she's] ever made." Sereno was a nationally known club with alumni that have gone on to play in college, on professional teams, and for national teams. Ertz played with the team from 2004 to 2010 on the U-13 through U-19 teams. She won the state title nine times during her time there and was captain of the team.
Ertz attended Dobson High School in Mesa from 2006 to 2010, where she volunteered as a student athletic trainer all four years. She never played for the soccer team at the school, instead opting to devote her time to playing for Sereno. While at Dobson, Ertz was a member of the National Honor Society.
Ertz attended Santa Clara University, where she majored in communications and played as a midfielder for the Broncos women's soccer team. In 2010, as a college freshman, she played in 20 games, starting 16 and accumulating 1,519 minutes of playing time. At the end of the season, she led the team in assists with five and recorded the third-most shots on the team with 31. She was named WCC Freshman of the Year and received NSCAA All-West Region Second-Team, Soccer America All-Freshman First-Team, All-WCC Second-Team, and WCC All-Freshman team honors. As a sophomore, Ertz started all 21 games and led the Broncos with nine goals and four assists. She scored four game-winning goals in matches against Cal Poly, WSU, Cal and Nevada. She was a MAC Hermann Trophy semi-finalist and was named to the NSCAA All-American First-Team as well as the All-WCC First-Team. In her junior year, Ertz started 15 of the 16 games she played and led the Broncos with eight goals and was second on the team with five assists. She scored three game-winning goals and recorded an assist in the first round of the NCAA Women's Soccer Tournament in a match against Long Beach State. She was subsequently named to the All-WAC First Team and NCAA Division I Women All-West Region First Team. She was a MAC Hermann Trophy semi-finalist and was named U.S. Soccer Young Female Athlete of the Year. In 2013, Ertz played in 22 games and led the team with eight assists and four game-winning goals. She made a total of 12 goals in the season and recorded an assist in the first round of the NCAA Women's Soccer Tournament in a match against University of California at Berkeley. At the end of the season, she was named to the NSCAA All-American First Team, NSCAA All-West Region First Team, All-WCC First Team and College Sports Madness All-WAC First Team. She was also named WCC Player of the Year and College Sports Madness WCC Player of the Year.
On January 17, 2014, Ertz was selected third overall in the first round of the 2014 NWSL College Draft by the Chicago Red Stars. She subsequently signed with the team for the 2014 season. She made her first appearance for the team on April 19, 2014 in a match against the Western New York Flash. She scored the only goal of the match in the 59th minute. In the 2014 season, Ertz started in 21 matches and scored two goals. The Red Stars finished fifth in the regular season with a 9–7–8 record and did not advance to the playoffs. Ertz was named NWSL Rookie of the Year following the 2014 season.
In 2015, Ertz missed almost half of the NWSL season due to commitments with the United States women's national team at the FIFA Women's World Cup in Canada. She returned to the Red Stars on July 22 during a match against the Boston Breakers, which ended in 2–1 victory for the Red Stars. She made 11 appearances for the Red Stars during the 2015 season, playing 990 minutes. The Red Stars finished second in the regular season with a 8–3–9 record and advanced to the playoffs. The Red Stars faced FC Kansas City in the semifinals of the playoffs on September 13. Ertz started in the match, which ended in a 0–3 defeat for the Red Stars and they were eliminated from the playoffs. Following the 2015 season, Ertz was named to the NWSL Best XI.
Ertz made seven appearance for the Red Stars during the 2016 season before joining the national team in preparation for the 2016 Summer Olympics in Rio de Janeiro.
In the 2017 season, Ertz debuted in a new role in attacking midfield, scoring the winning goal in a 1–0 victory over FC Kansas City in week 2.
In 2006, Ertz attended the United States U-14 National Identification Camp. In 2009, she was called into a U-18 national team training camp from May 30 to June 7 at The Home Depot Center in Carson, California.
In 2012, Ertz competed in international under-20 youth soccer and scored a goal against Switzerland at the La Manga Tournament in Spain. Heading into the 2012 FIFA U-20 Women's World Cup, she had 13 caps and four goals for the U-20 team. Ertz captained the United States team to the Japan 2012 U-20 FIFA Women's World Cup; winning the 2012 CONCACAF Under-20 Women's Championship along the way. She played in three games in the qualifying tournament and scored three goals, including one in the 4–0 semifinal victory over Mexico that sent the USA to Japan. In Japan, Ertz captained her team to win the FIFA under-20 world cup, and won the Bronze Ball award herself.
In 2013, Ertz played for the U-23 team in the Four Nations Tournament in La Manga, Spain. The team won the tournament, beating England in the final on March 7.
Ertz was first called up to the national team in January 2013, when she was on the 29-player roster for a training camp leading up to two matches against Scotland in early February. Ertz made her first appearance for the national team in their first match of the year on February 9, 2013 against Scotland. She came in for Becky Sauerbrunn in the 83rd minute to help the United States win the match 4–1.
Ertz traveled to Europe with the national team for matches against Germany and the Netherlands in early April. On April 9, Ertz started in the midfield in the match against the Netherlands. Ertz scored in the 73rd minute but the referee ruled that she was offside and the goal was called back. The United States won the match, 3–1. In late May, Ertz was named to the 21-player roster that traveled to Canada to train in preparation for a match against Canada on June 2. She did not appear in the match.
Ertz started off 2014 at a national team training camp from January 8 to 15 at U.S. Soccer's National Training Center in Carson, California. Ertz was not named to the roster for the 2014 Algarve Cup in March. In late April, Ertz was named to a 22-player roster for a match against Canada on May 8. She was then named to the roster for two games against France on June 14 and 19. Ertz was named to a 19-player roster for a match against Switzerland on August 20 in Sandy, Utah. She came in for Sauerbrunn in the second half and the United States went on the win 4–1.
Ertz joined the national team for a training camp at the end of August in order to prepare for two matches against Mexico in September as well as the 2014 CONCACAF Women's Qualifying tournament in October. Initially, she was not named to the roster for the 2014 CONCACAF Women's Championship that served as a qualification for the 2015 FIFA Women's World Cup. However, one day before the team's first match of the tournament, Ertz replaced an injured Crystal Dunn on the roster. The United States qualified for the 2015 FIFA Women's World Cup after a semifinal win against Mexico on October 24. Following the CONCACAF Qualifying tournament, Ertz was named to the 24-player roster for the International Tournament of Brasília in Brazil that took place from December 10 to 21. Ertz made one appearance in the opening game of the tournament on December 10 against China, which resulted in a 1–1 draw. The final game against Brazil was a 0–0 draw, but the tournament title was given to Brazil, who had more points from the group stage.
Ertz started off 2015 at a 21-day training camp in 2015 from January 5 to 25 at the U.S. Soccer National Training Center in Carson, California. Following the training camp, she was named to the 24–player team that would travel on a 13-day trip to Europe for matches against France and England in mid-February. On February 21, Ertz was named to the 25-player roster for the 2015 Algarve Cup in Portugal. She started three matches of the tournament, including in the final against France on March 11. During the game, Ertz scored her first international goal in the 7th minute to help the United States defeat France 2–0.
On April 14, 2015, Ertz was named to the 23-player roster that would represent the United States at the 2015 FIFA Women's World Cup. She was one of the five United States players that played every minute in all seven matches for the United States during the World Cup. In the 59th minute of the team's semifinal match against Germany on June 30, Ertz pulled down Germany's Alexandra Popp inside the penalty box and was given a yellow card. Celia Sasic of Germany took the subsequent penalty kick but missed the net. The United States went on to win the match 2–0 to advance to the World Cup final. In the final, the United States faced Japan on July 5. In the 52nd minute, Ertz attempted to block a free kick but instead scored an own goal. However, the United States still went on to win the match and the World Cup title. Following the tournament, Ertz was named to the FIFA Women's World Cup All-Star Team. She joined the national team on a Victory Tour following their World Cup win that started in Pittsburgh, Pennsylvania on August 16 and ended in New Orleans, Louisiana on December 16.
Ertz joined the national team for their first training camp of the year at the U.S. Soccer National Training Center in Carson, California from January 5 to January 21. She was then named to the 20-player roster for 2016 CONCACAF Women's Olympic Qualifying tournament. The United States qualified to the 2016 Olympic Games in Rio de Janeiro after a semifinal win against Trinidad and Tobago on February 19. The United States won the tournament after defeating Canada 2–0 on February 21.
Ertz was named to the roster for the 2016 SheBelieves Cup that took place from March 3 to 9. She came in for Alex Morgan in the 80th minute of the team's opening match of the tournament on March 3 against England. She also made appearances in other two matches of the tournament, helping the United States win the 2016 SheBelieves Cup with a 2–1 win over Germany in their final game.
Ertz joined a 23-player roster for a training camp ahead of two matches against Colombia in early April. In the second match on April 10, Ertz played all 90 minutes and scored two goals to help the United States defeat Colombia 3–0. Ertz was on the roster for another two-game series against Japan in early June. She started in both games and scored a goal in the 27th minute of the second match on June 5.
On July 12, 2016, Ertz was named to the 18-player team that would represent the United States at the 2016 Olympic Games in Rio de Janeiro. She made her Olympic debut on August 3 in the team's opening match against New Zealand, a 2–0 victory. She did not appear in the team's second group match on August 6 due to a sore groin.
She is married to Zach Ertz, a tight end for the Philadelphia Eagles in the National Football League. The two met in college while attending a Stanford Cardinal baseball game. On February 26, 2016, the couple got engaged at the same baseball stadium where they met. They married on March 26, 2017, in Goleta, California.
Ertz was featured along with her national teammates in the EA Sports' FIFA video game series in FIFA 16, the first time women players were included in the game.
Following the United States' win at the 2015 FIFA Women's World Cup, Ertz and her teammates became the first women's sports team to be honored with a Ticker Tape Parade in New York City. Each player received a key to the city from Mayor Bill de Blasio. In October of the same year, the team was honored by President Barack Obama at the White House.WCC Freshman of the Year: 2010
NSCAA All-West Region Second Team: 2010
Soccer America All-Freshman First Team: 2010
All-WCC Second Team: 2010
WCC All-Freshman Team: 2010
MAC Hermann Trophy Semi-Finalist: 2011, 2012
NSCAA All-American First Team: 2011, 2013
All-WCC First Team: 2011, 2012, 2013
Preseason All-WCC: 2011
Top Drawer Soccer Team of the Year: 2012
NCAA Division I Women All-West Region First Team: 2012
NSCAA All-West Region First Team: 2013
WCC Player of the Year: 2013
College Sports Madness WCC Player of the Year: 2013
College Sports Madness All-WCC First Team: 2013
NWSL Rookie of the Year: 2014
NWSL Best XI: 2015
U.S. Soccer Young Female Athlete of the Year: 2012
FIFPro: FIFA FIFPro World XI 2015
CONCACAF U-20 Women's Championship: 2012
FIFA U-20 Women's World Cup: 2012
Four Nations Tournament: 2013
CONCACAF Women's Championship: 2014
Algarve Cup: 2015
FIFA Women's World Cup: 2015
2016 CONCACAF Women's Olympic Qualifying: 2016
SheBelieves Cup: 2016