Tanner Vallejo was born on December 16, 1994, in Penn Valley, California. He is a linebacker for the Washington Redskins in the NFL.
In his early years, Vallejo attended Nevada Union High School where he started playing football. In his sophomore year, he earned first-team All-Sierra Foothill League honors, in addition to first-team all-metro and first-team All-Sac-Joaquin Section accolades and he recorded 132 tackles, two sacks, five forced fumbles, and one fumble recovery. As a junior, he named league's most valuable player after recording 158 tackles, two sacks, an interception, six forced fumbles, and one fumble recovery. He also garnered first-team all-metro, Sac-Joaquin Section First Team, and second-team all-state honors. In his senior year, Vallejo earned a second-straight Sierra Foothill League Defensive Most Valuable Player honor and was also second-team all-state, first-team All-SFL, first-team All-Sac-Joaquin Section, all-metro and a MaxPreps All-American. He registered 129 tackles, two sacks, an interception, three forced fumbles, three fumble recoveries and scored 13 touchdowns during his prep career.
After finishing high school, Vallejo committed to the University of Boise State to play college football. As a freshman, he appeared in 11 games during his debut season with the Broncos, including six starts. He made his first career start against Nevada, and ended up starting six of the last seven games of the year...recorded 51 tackles where 28 of them were solo. As a sophomore, he was named to All-Mountain West Second Team and finished fifth in the conference with 16.5 tackles-for-loss. He led the team with 100 tackles where 64 of them were solo and three fumble recoveries. He scored two defensive touchdowns where one of them came off a 31 fumble return against Connecticut September 13 which was his first career TD and his other defensive touchdown came off a 63-yard interception against Fresno State on December 6 in the Mountain West Football Championship. He made a career-high 13 tackles, 3.0 for loss, and returned an interception 63 yards for a touchdown in the MW Football Championship against Fresno State en route to being named game's Defensive MVP on December 6 and led Broncos with 14 tackles including 1.5 sacks, and earned Fiesta Bowl Defensive MVP honors in win against No. 10 Arizona on December 31.
As a junior in 2015, he was named All-Mountain West honorable mention. Vallejo appeared in 12 games, making 10 starts, finishing third on the team with 57 tackles (32 solo), tying for second with a pair of forced fumbles and tying for fourth with 8.0 tackles-for-loss and also making a sack. In his senior year, he appeared and started nine games, finishing fourth on the team with 69 tackles (39 solo), including 6.0 tackles-for-loss. He opened the season on the preseason watch lists of the Butkus Award and the Bronko Nagurski Trophy and was named All-Mountain West honorable mention.
After graduating from college, Vallejo decided to enter the 2017 NFL Draft where he was selected in the sixth round by the Buffalo Bills. On May 11, 2017, the Buffalo Bills signed Vallejo to a four-year contract but was waived on September 1, 2018. On September 2, 2018, Vallejo was claimed off waivers by the Cleveland Browns where he played in 13 games and was waived by the team on February 4, 2019. He then was claimed off waivers by the Arizona Cardinals on February 5, 2019.
On September 2nd, 2019, Vallejo signed with the Washington Redskins.
On March 17, 2021, Vallejo re-signed with the Cardinals on a two-year, $4.1 million contract.