Gillespie grew up in Ocala, Florida and attended Vanguard High School.[1] He played safety and running back and returned punts for the Knights. As a senior, Gillespie had 40 tackles and two interceptions on defense and rushed for 555 yards and seven touchdowns with a 14.2 rushing averaged on offense.[2] He committed to play college football at Missouri over offers from Iowa State, Marshall, New Mexico and Troy.[3]
Gillespie played for the Missouri Tigers for four seasons. As a freshman, he played in seven games. He started the final eight games of his sophomore season and finished with 48 tackles.[4] As a junior, Gillespie recorded 50 tackles, 4.0 tackles for loss, and one sack with seven pass breakups a forced fumble.[5] He had 46 total tackles and four pass breakups in nine games in his senior season.[6] While at Missouri, Gillespie was a member of the Omega Psi Phi fraternity.[7]
Gillespie was selected by the Las Vegas Raiders in the fourth round, 143rd overall, of the 2021 NFL Draft.[11] On May 17, 2021, he signed his four-year rookie contract with the Raiders.[12] He entered his rookie season as the backup strong safety and mostly played in special teams. He was placed on injured reserve on November 17, 2021.[13] He was activated on December 25.
On August 31, 2022, Gillespie was claimed off waivers by the Jacksonville Jaguars.[16] He was waived on December 19, and re-signed to the practice squad.[17] On February 9, 2023, Gillespie signed a reserve/future contract with the Jaguars.[18] He was waived on May 1.
On May 2, 2023, Gillespie was claimed off waivers by the Houston Texans.[19] He was waived/injured on August 23, 2023.[20] He was released on September 1.
On December 5, 2023, Gillespie was signed to the Kansas City Chiefs practice squad.[21] He was released on January 5, 2024.[22] He was re-signed on February 22, 2024, then waived on May 4, but re-signed on July 22.[23][24]
