Meredith was a three-year letter winner in football, playing at quarterback for St. Joseph High School (Westchester, Illinois). His parents are Lonnie and Tonjua Meredith.
Meredith attended Illinois State. He redshirted his first season and then spent the 2011 and 2012 seasons as a backup quarterback. In 2013, he transitioned to wide receiver and led the team in receptions in both 2013 and 2014. In 2014, he led the team with 66 receptions for 1,061 yards receiving, with nine touchdowns in 15 games. Being a redshirt senior with no eligibility remaining he entered the 2015 NFL Draft, but he was not invited to the NFL Combine. He impressed scouts at the Northwestern University pro day enough to earn several free agent offers.
During the 2015 NFL Draft, Meredith was the victim of a prank call, a person pretending to be New England Patriots head coach Bill Belichick stating that the team would be taking him with the 97th overall pick; instead, the Patriots took defensive end Geneo Grissom and Meredith went undrafted.
Meredith signed with the Chicago Bears as an undrafted free agent.
On September 20, 2015, Meredith recorded his first NFL reception against the Arizona Cardinals. On October 11, Meredith caught a season-high four receptions for a season-high 52 yards against the Kansas City Chiefs. At the end of the 2015 season, Meredith finished with 11 receptions for 120 yards.
Meredith began his second season as the Bears' fifth wide receiver on their depth chart behind Alshon Jeffrey, Kevin White, Eddie Royal, and Joshua Bellamy.
On September 25, 2016, he made his season debut against the Dallas Cowboys and finished with two receptions for 24 receiving yards. On October 9, 2016, Meredith received his first career start in place of Kevin White against the Indianapolis Colts and caught nine passes for 130 receiving yards and a touchdown. He caught his first career touchdown reception on a 14-yard pass from Brian Hoyer and fumbled twice, while losing one in the fourth quarter, costing the Bears the game. The following game, he caught eleven passes for 113 receiving yards during a 17–16 loss to the Jacksonville Jaguars, his second consecutive career 100-yard game. In Week 10, Meredith caught a season-long 50 yard touchdown reception during a 36–10 loss over the Tampa Bay Buccaneers.
On December 18, he caught nine passes for 104 receiving yards during a 30–27 loss to the Green Bay Packers. The following week, Meredith caught nine passes for a season-high 135 receiving yards and a touchdown against the Washington Redskins. It marked his fourth game of the season with over 100 yards receiving. In the Bears' 38–10 season finale loss to the Minnesota Vikings, Meredith threw his first career touchdown on a 2-yard pass to quarterback Matt Barkley. He threw the pass to a wide open Barkley after receiving a handoff from running back Jeremy Langford, who, in turn, received it on a direct-snap.
Meredith finished the 2016 season with 66 catches for 888 yards and four touchdowns.
Meredith was the top wide receiver on the Bears' depth chart heading into the 2017 NFL season. He suffered a severe knee injury during the Bears' third preseason game against the Tennessee Titans. Further medical review revealed that Meredith tore his ACL and also suffered "other damage" to his knee that will force him to miss the entire 2017 season. He was placed on injured reserve on September 2, 2017.