Mendoza, a graduate of Adolfo Camarillo High School, was named the Los Angeles Times "Player of the Year" in 1998. During her junior and senior years, she was named Camarillo High School "Female Athlete of the Year." Mendoza was also a member of the high school basketball team and was the team MVP in both her junior and senior years.
Mendoza began her career as a 1999 First Team All-American and All-Pac-10 honoree. Included with her recognition, she was named conference "Newcomer of The Year." She broke the Cardinal records for season batting average and RBI totals while ranking top-10 for her hits.
On March 6, 1999 in defeating Illinois State, Mendoza hit a single game career high 4 hits off pitchers Corey Harris, Tammy Millian and Jamie Bagnall. Later that month, for the week of March 8, she was named National Fastpitch Coaches Association "Player of The Week" after hitting .631 (12/19) with 11 RBIs, 4 home runs, a triple and two doubles for a slugging percentage of 1.473.
The sophomore's season saw her again earn First Team citations for the NCAA Division I and the Pac-10. She added conference "Player of The Year" to her collection and broke her own record for batting average with a then school and career best .474 statistic, which also led the NCAA. She also claimed new records for hits, home runs, doubles, slugging and stolen bases, which all still rank top-10 for a season at Stanford.
From February 29 through March 22, 2000, Mendoza went on a school record 19 consecutive game hit streak. She batted .561 (32/57) to accompany 15 RBIs, 4 home runs, doubles and base on balls, striking out just once with a slugging of .842.
Mendoza continued her success for the Cardinal with her third All-American and All-Pac-10 citations. She posted top-10 season records in virtually every category, still currently ranking second in home runs and stolen bases.
For the March 14 week, she earned NFCA "Player of The Week" recognition for her performance of .461 (12/26) with 4 RBIs, three home runs, a double, three walks and a .846 slugging.
Mendoza helped lead Stanford to their first ever Women's College World Series appearance. The Cardinal were ousted on May 27 by the Arizona Wildcats despite wins over California Golden Bears and LSU Tigers. The outfielder, however, was named to the All-Tournament Team for hitting .250 with an RBI and a double to her credit. It was her only appearance at the series.
For a final season, Mendoza earned First Team citations for both conference and the NCAA. With her fourth straight honor from the NCAA, Mendoza joined elite company as only the fifth player to accomplish the feat then. That year she also tied her home run record and ranked top-10 in almost every other category.
The week of March 4, she was named NFCA's "Player of The Week" for a third time. She had hit .647 (11/17) with a home run, 5 doubles and 1.117 slugging. Later that season on May 8 with a 10–2 victory over the San Jose State Spartans, Mendoza drove in a career best 6 RBIs, 4 coming off her 50th career home run swing with Carol Forbes pitching.
In her four years Mendoza currently holds the career records in average, hits, home runs, slugging, runs and stolen bases. Her career doubles (ranked 5th in the NCAA all-time), triples, RBIs and walks are still top-10 records. She was named the Stanford Athlete of the Year three times. She was also named Pac-10 Player of the Week three times, a top 25 finalist for USA Softball Collegiate Player of the Year, and the Speedline Invitational Tournament MVP. Mendoza graduated from Stanford with a Master's Degree in Social Sciences and Education.
In 2004, Mendoza was a starting outfielder for Team USA at 2004 Athens Olympic Games. Prior to the tournament, Mendoza hit .380 on the "Aiming For Athens" tour with 42 RBIs and 10 home runs. On August 14, Mendoza had two hits and two RBIs with a triple vs. Italy. She repeated her performance on August 19 against host Greece, with a double in that game. Team USA won the gold medal on August 23, though Mendoza was shut out by Australia. Overall, she went 5/20 (.250) scoring five times herself and hitting in 5 RBIs with a .400 slugging.
In 2008, Mendoza was again an outfielder for Team USA and led in almost every category on the "Bound 4 Beijing" Tour. She hit .495 with 107 RBIs and a .971 slugging. At the Beijing Olympic Games, she drove in 4 RBIs vs. Chinese Taipei on August 14. In the finale, Mendoza was again shut out and her team won the silver medal, losing to Japan on August 21.
In addition, straight out of college, Mendoza went directly onto the US team. In 2003 and 2007, she was a gold medalist at the Pan American Games. She also won the silver medal at both the World Cup and Japan Cup. In 2006, Jessica was named the USA Softball "Female Athlete of the Year." She played for Team USA in the World Cup again in 2007, this time bringing home that gold medal. She went 11/18 with a double, three home runs, and 16 RBIs. Mendoza won the ISF Women's World Championship, hitting .500 with 5 home runs and 16 RBIs. In 2008, she was named to the Canada Cup All-Star Team. Mendoza declined an invitation to play for the US in 2011 to focus on National Pro Fastpitch.
Mendoza joined the National Pro Fastpitch in 2005 with the Arizona Heat. She hit a league best (though in limited playing time) .491 her rookie year. After returning from maternity leave and a role with Team USA, Mendoza signed with the USSSA Pride. In her two seasons with the Pride, Mendoza hit .284 and .377 respectively. The same two years her teams made the Cowles Cup Championship, winning the title in 2010. Mendoza was shut out vs. the Chicago Bandits's trio of Kristina Thorson, Nikki Nemitz, and Jessica Sallinger. In the other finale, Mendoza was 2/4 with a double off Monica Abbott in a rematch with the Bandits who ultimately won 10–3 on August 21. Once again Mendoza and the Pride made the Cowles Cup Championship but lost to the Chicago Bandits. Mendoza was shut out but walked twice.
Mendoza works for ESPN and is currently a member of ESPN's Sunday Night Baseball broadcast team. She also is a color analyst during the Women's College World Series and is a sideline reporter for ESPNU.
On June 30, 2014, Mendoza began working as an analyst on ESPN's Baseball Tonight. She appears on the Monday editions of the show.
On June 16, 2015, Mendoza became the first female broadcaster in the booth for ESPN's College World Series coverage with Karl Ravech and Kyle Peterson. On August 24, Mendoza was the first female analyst for a Major League Baseball game in the history of ESPN, during a game between the St. Louis Cardinals and the Arizona Diamondbacks. Six days later, Mendoza filled in for suspended color commentator Curt Schilling for the Cubs-Dodgers game on Sunday Night Baseball. Cubs pitcher Jake Arrieta pitched a no-hitter in the game. John Kruk, Dan Shulman and Mendoza called the 2015 American League Wild Card Game on October 6, and Mendoza became the first female analyst in MLB postseason history. On January 13, 2016, ESPN announced that Mendoza would join the Sunday Night Baseball broadcast team full-time.
A daughter of Karen and Gil Mendoza, Jessica has one brother, Walt, and two sisters, Elena and Alana. Her father played football for 4 years for Fresno State University. Mendoza is married to Adam Burks and they have two sons named Caleb Ashton and Caden Adam. She is of Mexican descent.
Mendoza is the Women's Sports Foundation President. She is an athletic ambassador for Team Darfur and board member of the National Education Association.