[11] Van Noy was projected as a first or second round pick in the 2013 NFL draft,[12] but opted to remain at BYU for his senior season.

In his final collegiate season, he recorded 70 total tackles, 17 tackles-for-loss, 4.0 sacks, two interceptions, six passes defended, and two fumble recoveries.

[15] On January 25, 2014, Van Noy played in the 2014 Senior Bowl and recorded two solo tackles and one sack as part of Jacksonville Jaguars' head coach Gus Bradley's South team that defeated the North 20–10.

On March 14, Van Noy participated at BYU's pro day, but chose to stand on his combine numbers and only performed positional drills.

He attended pre-draft visits with multiple teams, including the Atlanta Falcons, the Baltimore Ravens, the Detroit Lions, and the Jaguars.

[18][19] At the conclusion of the pre-draft process, Van Noy was projected to be a second round pick by NFL draft experts and scouts.

[30] On August 28, the Lions announced that Van Noy had successfully undergone muscle core surgery, but offered no timetable on his return.

[31] On November 9, Van Noy made his professional regular season debut and registered two solo tackles during a 20–16 victory against the Miami Dolphins in Week 10.

[37] Van Noy was inactive as a healthy scratch for the Lions' Week 5 loss to the Arizona Cardinals due to the return of DeAndre Levy.

[38] On October 25, 2015, Van Noy recorded two solo tackles and made his first career sack during the Lions' 28–19 loss to the Minnesota Vikings in Week 7.

On November 20, Van Noy played in his first game as a Patriot and recorded three combined tackles and one sack during their 30–17 win at the San Francisco 49ers in Week 11.

[45] On December 4, he recorded five combined tackles, broke up a pass, and made his first career interception during a 26–10 win against the Los Angeles Rams.

Van Noy intercepted a pass by Rams' rookie quarterback Jared Goff during the third quarter after the play was disrupted by Jabaal Sheard.

As both a Lion and Patriot in total, Van Noy finished the season with 52 combined tackles (32 solo), three pass deflections, one sack, and one interception in 14 games with nine starts.

On February 5, he appeared in Super Bowl LI and made one tackle and was credited with half a sack during the Patriots' 34–28 overtime victory against the Falcons.

[48][49][50] The Patriots came back from a 25-point deficit in the third quarter to defeat the Falcons to earn Van Noy the first Super Bowl victory of his career.

On January 21, 2018, Van Noy made nine combined tackles, a pass deflection, and one sack as the Patriots defeated the Jaguars 24–20 in the AFC Championship Game.

On February 4, Van Noy started in Super Bowl LII and made five combined tackles as the Patriots lost 41–33 to the Philadelphia Eagles.

[58] On October 21, 2018, Van Noy registered six solo tackles and scored his first career touchdown after returning a blocked punt during the Patriots 38–31 victory at the Bears in Week 7.

During the third quarter, he recovered a punt attempt by Bears' punter Pat O'Donnell that was blocked by Hightower and returned it 29 yards for a touchdown.

[61] Against the New York Jets on December 30, Van Noy scored his second career touchdown after recovering a fumble forced by teammate Adam Butler.

[65] In Week 4 against the Buffalo Bills, Van Noy recorded a team-high 8 tackles, 2 sacks on Josh Allen, and forced 2 fumbles in the 16–10 win.

[68] In Week 7 against the Jets, Van Noy recovered a fumble by quarterback Sam Darnold forced by teammate John Simon in the 33–0 win.

[69] In Week 9 against the Ravens, Van Noy forced a fumble on running back Mark Ingram II that was recovered by teammate Lawrence Guy in the 37–20 loss.

[83][84] In the 2021 season, he appeared in 16 games with eight starts,[85] recording five sacks, 66 total tackles, one interception, ten passes defended, and two forced fumbles.

[92] In Week 1 against the Kansas City Chiefs, Van Noy would post just one solo tackle, before going down with an eye injury in the third quarter, which was later disclosed to be an orbital bone fracture.

[93] Van Noy did not provide a timetable for his injury, stating simply that it was "a pretty good fracture," and that he was still going through tests with specialists; he ultimately did not miss any time.

[98] Van Noy proposed to on-again, off-again girlfriend[99] the former Miss Utah USA winner, Marissa Powell in December 2013.