Irwin played college football at Stanford.[4] He finished his college career with 152 receptions for 1,738 receiving yards and five touchdowns, while also returning 20 punts for 230 yards.[5] He also had at least one reception in 40 consecutive games.[6]
Irwin went undrafted in the 2019 NFL draft. He signed with the Miami Dolphins in April 2019.[5] He was released from the Dolphins on August 31, 2019.[8]
On September 5, 2020, Irwin was waived by the Bengals and signed to the practice squad the next day.[12]
In Week 16 against the Houston Texans, Irwin was elevated to the active roster, and made the first reception of his career, a 5-yard pass from quarterback Brandon Allen.[13] He reverted to the practice squad after the game.[14]
2021
On September 1, 2021, Irwin was waived by the Bengals and re-signed to the practice squad.[15] He was elevated to the active roster on September 15, 2021.[16]
In Week 4, Irwin caught his only reception of 2021 for a 25-yard gain against the Jacksonville Jaguars.[17]
2022
On March 21, 2022, Irwin re-signed with the Bengals.[18] He was waived on August 30, 2022, and signed to the practice squad the next day.[19][20]
In Week 11, against the Pittsburgh Steelers, Irwin caught his first professional touchdown from quarterback Joe Burrow on a goal-line pass.[21] On November 22, 2022, Irwin was signed to the active roster.[22] Irwin caught his second career touchdown pass in Week 14 against the Cleveland Browns, when the Bengals called a Flea flicker that left him open in the backfield for a 35-yard touchdown.[23]
In Week 16 against the New England Patriots, Irwin played his most impressive professional outing to date. Out of four targets, he netted three receptions for 45 yards and two touchdowns. He narrowly missed a pass in the end zone that could have resulted in a third touchdown, which would have given him a perfect reception percentage in the 22–18 victory.[24] Irwin played in nine games in the 2022 regular season. He finished with 15 receptions for 231 receiving yards and four receiving touchdowns.[25]
2023
Irwin made his first catch of the season in Week 4 against the Tennessee Titans, pulling in one reception for 17 yards. The following week against the Arizona Cardinals, Irwin was named a starting wide receiver due to Tee Higgins being ruled inactive for a rib injury. He took advantage of this opportunity by pulling in 8 catches for 60 yards. Irwin scored his first touchdown of the season in Week 10 against the Houston Texans. In addition to his lone touchdown, he finished the season with 25 receptions for 316 yards, both career bests for him.[26]
2024
Irwin re-signed with the Bengals on March 19, 2024.[27] He competed with Andrei Iosivas, Charlie Jones, and Jermaine Burton for the Bengals' third starting wide receiver position in the preseason, with Iosivas ultimately winning the job, and Irwin being named the fourth wide receiver on the depth chart to begin the year.[28]