[23] That year he also helped the Trojans to a victory in the Rose Bowl[4] over the Penn State Nittany Lions, catching seven passes for 133 yards and a receiving touchdown over the course of the game.

[24] After the 2016 season, Smith-Schuster announced on Twitter[4] that he had decided to forgo his senior year and enter the 2017 NFL draft,[25] before signing with sports agency Roc Nation.

"[26] Though he left before graduation, Smith-Schuster later returned to take summer courses at USC in order to work towards finishing his university degree.

[36] Smith-Schuster entered training camp competing with Sammie Coates, Darrius Heyward-Bey, Eli Rogers, Marcus Tucker, and Justin Hunter to be the Steelers' third option at wide receiver on their depth chart.

He was named the sixth wide receiver on the Steelers' depth chart to begin the regular season behind Antonio Brown, Martavis Bryant, Heyward-Bey, Rogers, and Hunter.

[40] During the Vikings game, Smith-Schuster became the youngest NFL player to score a touchdown since running back Andy Livingston in 1964.

[42][43] Smith-Schuster started at wide receiver in place of Martavis Bryant, who was benched by head coach Mike Tomlin after publicly asking for a trade.

[47] On December 5, Smith-Schuster was suspended for one game after delivering a blindside block to Bengals' linebacker Vontaze Burfict in Week 13.

[55] On January 14, 2018, Smith-Schuster started in his first playoff game and made three receptions for five yards and a late touchdown in a narrow 45–42 loss to the Jacksonville Jaguars in the Divisional Round.

[57] Smith-Schuster entered training camp slated as a starting wide receiver after the Steelers traded Martavis Bryant to the Oakland Raiders for a third-round pick in the 2018 NFL draft.

[58] Tomlin named Smith-Schuster a starting wide receiver to begin the regular season, alongside Antonio Brown.

[60] He followed that performance up with a career-high 13 receptions for 121 receiving yards and a touchdown in a 42–37 loss to the Kansas City Chiefs.

[62] Smith-Schuster broke another NFL record on November 25, against the Denver Broncos when he became to the first player ever to have two offensive touchdowns of at least 97 yards.

[65] This would ultimately be one of the causes of the Steelers missing the playoffs that season, as wins by the Baltimore Ravens and Indianapolis Colts the following week officially eliminated them.

[69] Smith-Schuster made his first career Pro Bowl in 2018 as an alternate, after Brown announced that he would not participate in the game because of an injury.

[72] Prior to the start of the season, the Steelers traded Antonio Brown to the Raiders making Smith-Schuster the team's number one wide receiver.

However, after the game went into overtime, he fumbled after catching a pass as Ravens cornerback Marlon Humphrey punched the ball out of Smith-Schuster's arms.

The fumble was costly as it allowed Baltimore to kick the game-winning field goal, sending the Steelers to a 26–23 overtime loss.

[85] Smith-Schuster was the subject of controversy after dancing on several other opponents' midfield logos for his TikTok followers prior to away games, including the Buffalo Bills and Bengals.

[87] Overall, Smith-Schuster rebounded in his contract year with the Steelers, catching 97 passes for 831 yards and a career-high nine touchdowns operating mainly out of the slot.

[92] In Week 5, Smith-Schuster suffered a severe shoulder injury during a win over the Broncos and was placed on injured reserve on October 16.

[93] Three months later, days before the Steelers' Wild Card Round game against the Chiefs, a 21-day window for him was opened, and he was activated on January 15 for that matchup.

[102] With 1:54 remaining and the game tied 35–35, Smith-Schuster was involved in a pivotal play where he was held by Eagles cornerback James Bradberry on third down.

[120] Smith-Schuster states he grew up a fan of USC and looked up to wide receivers Marqise Lee, Robert Woods, and Nelson Agholor.

[126] While injured during the 2019 season, Smith-Schuster participated in a live Thursday Night Football stream with TimTheTatman, for which he was paid $100,000.

[22][127] In February 2018, Smith-Schuster announced a partnership with the popular gaming group FaZe Clan to sell merchandise.

[128] He now has a YouTube channel using his full name that posts Call of Duty, Fortnite Battle Royale, and daily life videos that often feature his French bulldog Boujee.

The team intends to include content from other athletes and musicians and would establish its own gaming house after the 2020 NFL season ends.