Isaiah McKenzie was born on April 9, 1995, in Miami, Florida. He is a wide receiver in the National Football League.
McKenzie's first two years with the Georgia Bulldogs only saw him accumulate 190 receiving yards and 195 rushing yards, as he was primarily used as a kick returner. After Kirby Smart replaced Mark Richt as head coach, McKenzie was more prominently featured in the Georgia passing game. He caught 44 receptions for 633 yards and 7 touchdowns as a junior, becoming the Bulldogs' top receiver. Leading into the 2017 NFL Draft, McKenzie was compared to current Pittsburgh Steelers wideout Antonio Brown due to similarities in their kick-return abilities and athleticism.
McKenzie was drafted by the Denver Broncos in the fifth round, 172nd overall, in the 2017 NFL Draft. On September 11, 2017, in the season opener against the Los Angeles Chargers on Monday Night Football, McKenzie returned three punt returns for 48 net yards in his NFL debut. On September 24, against the Buffalo Bills, McKenzie recorded his first career rushing attempt, a four-yard carry. He totaled four receptions for 29 yards on the season. On September 10, 2018, McKenzie was waived by the Broncos and was re-signed to the practice squad. He was promoted to the active roster on October 25, 2018. He was waived again on November 2, 2018.
On November 5, 2018, McKenzie was claimed off waivers by the Buffalo Bills. McKenzie was used as the primary kick returner but has also seen significant time on offense. He scored his first NFL touchdown, rushing 6 yards on a jet sweep, against the Jacksonville Jaguars on November 25. Against the New York Jets, he was used in the run game after LeSean McCoy and Chris Ivory suffered injuries, rushing for 22 yards on four carries with another touchdown to go with 47 receiving yards in the 27–23 loss. He had 18 receptions for 179 receiving yards to go along with 66 rushing yards and two rushing touchdowns on the season.
McKenzie signed with the Indianapolis Colts in 2023.