[10] On January 27, 2018, Chark played in the 2018 Reese's Senior Bowl and made two tackles and caught five passes for 160 receiving yards and a touchdown as part of Houston Texans head coach Bill O'Brien's South team that defeated the North 45–16.

[13] Chark also attended a private workout for the Dallas Cowboys and pre-draft visits with the Buffalo Bills and Denver Broncos.

[14][15] At the conclusion of the pre-draft process, Chark was projected to be a second round pick by NFL draft experts and scouts.

[23] In the Jaguars' Week 2 victory over the New England Patriots, Chark recorded his first professional reception, which went for 13 yards.

[27] In Week 3 against the Tennessee Titans, Chark caught four passes for 76 yards and his third receiving touchdown of the season in the 20–7 win.

[28] In Week 5 against the Carolina Panthers, Chark caught eight passes for 164 yards (#8 in franchise history) and two touchdowns in the 34–27 loss.

[36] Chark suffered a fractured ankle during the Jaguars Week 4 game against the Cincinnati Bengals in the first quarter in the 24–21 loss.

[39] At the time of his trade, he was in the top 10 in Jaguars franchise history in receiving touchdowns (#7t), yards per reception (#5), and 100-yard games (#7t).

[47] In the season finale, Chark had just three receptions for 14 yards, but two were critical 4th-down conversions to set up the game winning touchdown, and kill the clock to eliminate the rival Green Bay Packers from the playoffs.

[48] On the season, Chark's 502 yards in the 11 games he played were third-best for the 9-8 Lions, behind Amon-Ra St. Brown and Kalif Raymond.

[50] In week 16 against the Green Bay Packers, Chark had his best showing of the season recording 6 catches for 98 yards and two touchdowns from Bryce Young in a 33-30 loss.