Gaillard spent five total seasons as a member of the Georgia Bulldogs football team, redshirting his true freshman season. He was moved from defensive line to offensive line during his redshirt year and appeared in two games at right guard in his first season of play.[3] He started all 13 of the Bulldogs games as a redshirt sophomore before moving to center before the 2017 season. He started every game for Georgia at center in each of his final two seasons.[4] After the end of his redshirt senior season, Gaillard was invited to play in the 2019 East–West Shrine Game.[5]
Gaillard was drafted by the Arizona Cardinals in the sixth round (179th overall) in the 2019 NFL draft.[9] The Cardinals acquired this selection from the Tampa Bay Buccaneers in exchange for the rights to head coach Bruce Arians. He signed a rookie contract with the team on May 9, 2019.[10] Gaillard spent his rookie season on the 53-man roster but did not appear in any regular season games.[11]
Gaillard made his NFL debut on September 13, 2020 in the season opener against the San Francisco 49ers when he took over at center following an injury to starter Mason Cole.[12] Gaillard made his first career start the following week against the Washington Football Team on September 20, 2020.[13] He took a leave of absence from the Cardinals after the birth of his daughter, and the team received a roster exemption for him on December 21, 2020; he returned to the team on December 28.[14] He was waived on July 21, 2021.[15]
Cincinnati Bengals
On July 22, 2021, Lamont was claimed off waivers by the Cincinnati Bengals.[16] He was waived on August 22, 2021.[17] He re-signed with the team's practice squad on September 21, 2021.
On February 15, 2022, Lamont signed a reserve/future contract.[18] He was waived on August 30, 2022.[19]
Miami Dolphins
On November 2, 2022, Gaillard was signed to the Miami Dolphins practice squad.[20] He was released on December 20.[21]
DC Defenders
On December 18, 2023, Gailard was signed by the DC Defenders of the XFL.[22] He was placed on Injured reserve on May 28, 2024.[23]