Laing was selected ninth overall in the 2012 CFL Draft by the Toronto Argonauts, but finished his college eligibility before signing with the team on May 15, 2013. He played for the Argonauts for three seasons finishing his stint with 72 tackles, 16 sacks, two forced fumbles and a safety. After his strong performance in the CFL, including CFL East All-Star honours in 2015, Laing drew the attention of NFL teams.
On February 29, 2016, Laing was signed by the Miami Dolphins of the NFL. On September 3, 2016, he was released by the Dolphins as part of final roster cuts. The next day he was signed to the Dolphins' practice squad. He was released on October 31, 2016.
Ottawa Redblacks
Only three days after his release from the Dolphins practice roster, he was signed by the Ottawa Redblacks of the Canadian Football League; just days before their final game of the regular season. Laing appeared in one regular season game with the Redblacks, as well as two post season games which included their Grey Cup victory over the Calgary Stampeders.
Toronto Argonauts (II)
On April 29, 2017, Laing signed with the Toronto Argonauts. Despite missing time with an injury, Laing recorded five sacks and a forced fumble during 11 regular season games played in 2017, and was named a CFL East All-Star for the second time. During the playoffs, Laing recorded the first sack of the 105th Grey Cup as part of a 27–24 Argonauts victory over Calgary. It was his second consecutive Grey Cup championship. Laing signed a two-year extension with Toronto the following January, and had a quick start to the 2018 season with three sacks in the first four games. Although the Argos missed the playoffs with a 4-14 record, Laing played in all 18 games, racking up 44 tackles and six sacks, and was named to his third CFL East All-Star team. Laing was also the team nominee for the CFL's Most Outstanding Defensive Player award. The 2019 season was similar for both Laing and the team; the team played poorly to start the year and missed the playoffs. Meanwhile Laing, who had another effective stretch of early season games in which he earned four sacks over three outings, won the Toronto award for Most Outstanding Defensive Player for the second consecutive year; he was additionally named Toronto's Most Outstanding Canadian Player. Laing was also named to his third consecutive Eastern All-Star team, the only member of Toronto's defense to be so honored.
Ottawa Redblacks (II)
Upon entering free agency, Laing signed a three-year contract with the Ottawa Redblacks on February 11, 2020.
