On January 22, 2021, it was announced that White Jr. had signed with the Montreal Alouettes.[3] White Jr. made his professional regular season debut on October 22, 2021, where he had two catches for 26 yards.[4] He played in five games in 2021 season, finishing with 18 receptions for 177 yards and two touchdowns.[4] He also made his postseason debut in the East Semi-Final where he had four catches for 39 yards in the loss to the Hamilton Tiger-Cats.[5]
In 2022, White had a breakout year where he played and started in the first 15 games of the regular season, recording 53 catches for 722 yards and two touchdowns.[5] However, his season came to an end on October 10, 2022, in the Thanksgiving Day Classic against the Ottawa Redblacks where he tore three ligaments in his knee after being pushed out of bounds by Damon Webb.[6] With a recovery time of nine to 12 months, White sat out the entire 2023 season.[6] While he was medically cleared to play at the end of 2023, he was not fully recovered and was on the injured list when the Alouettes won the 110th Grey Cup.[6]
Upon returning healthy to the Alouettes in 2024, White suffered a rib injury and was added to the six-game injured list to start the season.[7] However, following a quick recovery, White made his season debut on June 20, 2024, against the Ottawa Redblacks where he had four receptions for 61 yards and two touchdowns.[4][7]