Treadwell attended Crete-Monee High School in suburban Chicago, where he finished his three-year football career as the second-leading receiver in Illinois prep history with 3,563 yards.[2] He played primarily as a wide receiver during his career, but he was also the team's quarterback as a freshman and also played on defense his sophomore through senior years. As a sophomore, he caught 58 passes for 811 yards and seven touchdowns. As a junior, he was named the NWI Times Offensive Player of the Year, Southland Conference Offensive Player of the Year and a first-team all-state pick when he recorded 75 catches for 1,391 yards and 18 touchdowns on offense and 45 tackles (10 for loss) and eight sacks on defense.[3] Treadwell was named the Chicago Tribune Player of the Year, NWI Times Offensive Player of the Year, and all-state first-team as a senior after leading Crete-Monee to a 14–0 record and the Class 6A state title; he hauled in 81 catches for 1,424 yards and 16 touchdowns and rushed for 257 yards and seven more scores on the ground, while on defense he compiled 56 tackles and six interceptions. For his senior season efforts, Treadwell was named an All-American selection by Under Armour, USA Today, MaxPreps and SuperPrep. As a standout basketball guard and forward, Treadwell averaged 13.0 points and 8.6 rebounds per game for the Warriors.
Regarded as Illinois’ top football recruit in 2013, Treadwell was rated a 5-star recruit by Rivals.com, Scout.com, 247Sports.com and MaxPreps and the nation’s No. 1 wide receiver by Tom Lemming, Rivals.com, and ESPN.com. He was listed as the No. 5 overall recruit in the nation by Rivals.com, No. 6 by MaxPreps, No. 19 by ESPN.com, No. 28 by 247Sports.com, and No. 30 by Scout.com. Checking in at 6'3" (1.91 m), 195 pounds (88 kg), Treadwell ran a reported 4.40 in the 40-yard dash according to 247Sports. He was also the No. 1 ranked wide receiver in the 2013 class at the 247Sports Composite Rankings. Treadwell committed to the University of Mississippi on November 30, 2012.[4] Treadwell's former high school teammate and close friend, Anthony Standifer, who is a defensive back at Ole Miss, was the one that initially got Treadwell interested in the Rebels.
A member of the highly-ranked 2013 University of Mississippi signing class, Treadwell played three seasons for the Rebels. He finished his career as the all-time leading pass catcher in Ole Miss history with 202 career receptions (seventh-most in Southeastern Conference (SEC) history) and ranks third in receiving yards with 2,393 and touchdowns with 21, as well as tied for second with nine career 100-yard receiving games. Treadwell managed at least one catch in all 35 games in which he played for the Rebels.
Treadwell exploded onto the college scene with a record-breaking rookie season, establishing Ole Miss' freshman records with 72 receptions for 608 receiving yards and five touchdown catches.[5] As a result of his outstanding play, he was named SEC Freshman of the Year by the league coaches, becoming the first player in school history to receive the distinction.[6] He also established a school freshman record with nine catches in his Rebel debut at Vanderbilt and matched that total again in the regular-season finale at Mississippi State. He played in every game of the season and made 12 starts as a slot receiver. In the season opener at Vanderbilt on August 29, Treadwell earned his first start in his college debut and made the most of it, breaking an Ole Miss freshman record with nine catches for 82 yards and hauling in a two-point conversion; he was named SEC Freshman of the Week for his performance.[7] In Week 4 at #1 Alabama, he had four catches for 51 yards, one rush for 1 yard and threw his lone career interception. Against #9 Texas A&M on October 12, Treadwell caught a team-high eight passes for 77 yards while scoring his first two collegiate touchdowns. In the Rebels' 34–24 victory over Arkansas, he contributed with a game-high eight catches for 39 yards and a touchdown. The next week against Troy, he collected four catches for 53 yards and two touchdowns, including a highlight-reel catch-and-run in which he broke five tackles on his way to the end zone. In the final game of the season at Mississippi State on November 28, Treadwell tied his own Ole Miss freshman record with nine catches for 57 yards. During the game, he also completed a 19-yard pass to quarterback Bo Wallace on a trick play and forced and recovered a fumble to regain possession after a Wallace interception.
On November 1, 2014, with 1:30 left in the game against #3 Auburn, Treadwell caught a screen pass and took it to the Tigers' 1 yard line before being tackled from behind and bending awkwardly. As a result of the gruesome injury, Treadwell broke his tibia and dislocated his ankle, and adding insult to the injury, he fumbled the ball, which was recovered in the end zone by Auburn's linebacker Cassanova McKinzy, sealing the game for the Tigers.[8][9][10][11]
On January 4, 2016, Treadwell announced he would forego his final year of eligibility at Ole Miss to enter the 2016 NFL draft.[12] Treadwell stated: "After sitting down with my family, we have decided it is time for me to take the next step in my career and enter the NFL draft; it's always been a dream of mine to play in the NFL, and I can't thank my teammates, coaches and our great fans enough for their unbelievable support since the first day I stepped foot on campus. No matter how far life may take us, I will always be an Ole Miss Rebel. God bless."[13]
On February 22, Treadwell announced to NFL.com that he would not take part in the 40-yard dash event at the combine, stating that he wanted more time before running it in front of NFL team scouts and general managers. He said he set his goal in the mid-to-high 4.4s or 4.5s. "I figured if I have enough time to work on it, I'll get the time I want," Treadwell said. He did perform in the vertical jump at the combine, and his 33-inch leap placed him in the bottom half of the wide receiver group. Measuring in at 6'2" (1.88 m), 217 pounds (98 kg) at Ole Miss' pro day, Treadwell confirmed the relatively slow 40-yard dash time that scouts anticipated; in his first attempt, he clocked a pedestrian 4.65, and on his second chance, he ran a 4.63 with a 1.62 10-yard split. However, the more surprising result for Treadwell, in fact, was not his 40-yard dash time but a disappointing 33+1⁄2-inch (0.85 m) vertical jump, a half-inch better than he did in Indianapolis. He also completed the 20-yard shuttle in 4.30 seconds and the 3-cone drill in 7.04 seconds. Based on his combine and Pro Day numbers, among the 43 wide receivers that were evaluated in Indianapolis, Treadwell’s 40-yard dash time would have placed him 28th. His twelve reps in the bench press was tied for 22nd within the group and his combine vertical jump tied for 23rd. His broad jump of 9'9" (2.97 m) ranked 12th and his campus numbers in the 20-yard shuttle and 3-cone drill would have placed 17th and 16th, respectively. After the workout, Treadwell stated: "I didn't run what I wanted to run, but it was fun. I'm proud of myself for what I did run most importantly. I'm just a playmaker, when I get into the game it's a different feel than the 40-yard dash."
"We all know Treadwell ran a 4.65 in the 40 at his pro day. So, either you believe in him and his game, or you don't. He's a natural hands catcher and will win 50–50 balls. He's also one of the best blocking wide receivers in this draft. He's physical, tough and has great hands. I think the Vikings got a winner."
Treadwell was selected as the 23rd overall pick by the Minnesota Vikings in the first round of the 2016 NFL Draft.[18] On April 29, it was announced that Treadwell, who wore No. 1 at Ole Miss, would wear No. 11 for the Vikings, a number that stayed ownerless after wide receiver Mike Wallace was released in March.[19]
In June 2016, after being selected by the Vikings, Treadwell created a minor controversy when he posted a photo of himself on social media wearing an Oakland Raiders baseball cap.
On August 12, 2016, Treadwell made his first appearance as a Viking in a preseason game against the Cincinnati Bengals, catching a game-high four passes for 41 yards from backup quarterback Shaun Hill and third-stringer Joel Stave.[20]
On November 6, 2016, Treadwell caught his first career NFL pass, which was a 15-yard reception from quarterback Sam Bradford in the first quarter against the NFC North division rival Detroit Lions.[21] The reception would be Treadwell's only one of the 2016 season. Despite having high hopes following the draft, Treadwell's rookie year was limited as he only appeared in nine games and finished the season with only one reception for 15 yards.[22]
2017 season
In Week 2, against the Pittsburgh Steelers, Treadwell had three receptions for 33 yards.[23] In the 2017 season, he recorded 20 receptions for 200 receiving yards.[24]
2018 season
In Week 2 against the Green Bay Packers, Treadwell scored his first professional touchdown in the 29–29 tie.[25] In the 2018 season, Treadwell finished with 35 receptions for 302 receiving yards and one receiving touchdown in 15 games and seven starts.[26]
2019 season
On May 1, 2019, the Vikings declined the fifth-year option on Treadwell's contract, making him a free agent in 2020.[27] He was released on August 31, 2019.[28] The Vikings re-signed Treadwell on September 24.[29] In Week 13 against the Seattle Seahawks on Monday Night Football, Treadwell caught one pass for a 58 yard touchdown during the 37–30 loss. This was Treadwell's first touchdown catch since the second game of the 2018 season.[30] He finished with nine receptions for 184 yards and a touchdown in 13 games and one start in the 2019 season.[31]
Atlanta Falcons
On March 25, 2020, Treadwell signed with the Atlanta Falcons before being released on September 5, 2020.[32] He signed to their practice squad on September 16, 2020.[33] He was placed on the practice squad/COVID-19 list by the team on November 17, 2020.[34] He was restored to the practice squad and subsequently promoted to the active roster on December 1, 2020.[35] Although seeing limited action in only five games of the 2020 season, he made six receptions on seven total targets for 49 yards and scored a single-season career-high of two touchdowns.[36]
Jacksonville Jaguars
On June 18, 2021, Treadwell signed with the Jacksonville Jaguars.[37] He was released on August 31, 2021, and re-signed to the practice squad the next day.[38][39] He was promoted to the active roster on November 6, 2021.[40] He finished the 2021 season with 33 receptions for 434 receiving yards and one receiving touchdown in 12 games and seven starts.[41]
On March 21, 2022, Treadwell re-signed with the Jaguars.[42] He was released on August 29, 2022.[43]
New England Patriots
On September 6, 2022, Treadwell was signed to the New England Patriots practice squad.[44] He was released on October 4, 2022.[45]
Arizona Cardinals
On October 12, 2022, Treadwell was signed to the Arizona Cardinals practice squad.[46] He was released on October 26, 2022.[47]
Seattle Seahawks
On November 1, 2022, Treadwell was signed to the Seattle Seahawks practice squad.[48] He was promoted to the active roster on December 20.[49] He appeared in six regular season games and one postseason game for Seattle in the 2022 season.[50]
Baltimore Ravens
On June 5, 2023, Treadwell signed with the Baltimore Ravens.[51] He was released on August 29, 2023 and re-signed to the practice squad.[52][53] On September 30, Treadwell was elevated to the active roster.[54] He was signed to the active roster on December 30, then released on January 15, 2024. He was signed back to the practice squad shortly after that. He was not signed to a reserve/future contract after the season and thus became a free agent when his practice squad contract expired.[55]
Indianapolis Colts
On July 24, 2024, Treadwell signed with the Indianapolis Colts.[56] He was released on August 27, and re-signed to the practice squad.[57][58]