Joshua Ballinger Lippincott Rosen was born on February 10, 1997, in Manhattan Beach, California, to Charles Rosen, an orthopedic spine surgeon, and Liz Lippincott, a former journalist. Rosen’s father is Jewish, and his mother is a Quaker. Rosen had a bar mitzvah and identifies as Jewish, saying in 2016: “In retrospect, being Jewish is a big reason why I should have considered UCLA. Just because of how Jewish Hollywood is, and they really want someone to look up to because they just don’t have professional athletes.” In an earlier profile, Rosen said he celebrates Christmas and considers himself “kind of an atheist.”
Rosen grew up playing tennis; at age 12 he was the No. 1-ranked player for his age group in Southern California and top-50 in the country, and he became a top-10 player in junior rankings. Right before high school, Rosen switched from tennis to football.
Rosen attended St. John Bosco High School, a Catholic high school in Bellflower, California, where he had a 4.3 GPA. As a senior, he was named the Los Angeles Times Player of the Year and the Long Beach Press-Telegram Dream Team Player of the Year after passing for 3,186 yards, 29 touchdowns, and four interceptions. He was named a 2014 USA Today High School All-American the Southern California Jewish Sports Hall of Fame’s Male High School Athlete of the Year. During his playing career, he passed for 11,175 yards and 90 touchdowns.
An economics major, Rosen began taking classes at UCLA in January 2015; he enrolled early so he could take part in spring practice and was named the Bruins’ starting quarterback. He was named the Pac-12 Freshman Offensive Player of the Year and earned Freshman All-American honors from USA Today, Sporting News, and Football Writers Association of America (FWAA). He was also named The Sporting News’ Freshman of the Year, Pac-12 Conference Offensive Freshman of the Year (coaches), and Pac-12 Newcomer of the Year (AP).
In 2016, Rosen was injured in an October 8 loss to Arizona State Sun Devils, when he threw for a then-career high 400 yards. He missed the rest of the season with a shoulder injury. He had surgery on his throwing shoulder to repair soft-tissue damage.
In 2017, he led the conference in passing yards per game and Rosen was voted second-team All-Pac-12. His 3,756 yards passing broke Brett Hundley’s single season school record. Rosen missed the Cactus Bowl after doctors did not clear him to play. During his time as UCLA, he was nicknamed “Chosen Rosen” and the “Chosen One.”
With his skills and size (6 ft. 4 in., 226 lb.) Rosen was one of the most highly rated players coming into the 2018 NFL Draft and was selected by the Arizona Cardinals in the first round (10th overall). On May 10, 2018, he signed a four-year deal worth $17.84 million with an $11 million signing bonus. He made his first regular season appearance in Week 3 of 2018, replacing starter Sam Bradford with 4:31 remaining against the Chicago Bears and the Cardinals trailing 16–14. Arizona lost the game. Nevertheless, Rosen became the starting quarterback for Week 4. Rosen finished his rookie season with 2,278 passing yards, 11 touchdowns, and 14 interceptions as the Cardinals finished 3–13 (3–10 with Rosen as starter).
The Cardinals drafted quarterback Kyler Murray first overall in the 2019 NFL Draft making Rosen expendable and he was traded to the Miami Dolphins. After starter Ryan Fitzpatrick failed to generate offense, Rosen was brought in to relieve him in the first two games and then replaced him as starter in game three. He was later benched after throwing for only 85 yards and two interceptions against the Washington Redskins. Rosen only appeared in one other game in 2019.
Rosen was released by the Dolphins in 2020 and signed by the Tampa Bay Buccaneers.