He played college football at Notre Dame, finishing as their all-time receptions leader at tight end with 180.

[1] He attended Covington Catholic High School in Park Hills, Kentucky.

As a senior in 2019, he was the Gatorade Kentucky Football Player of the Year after recording 49 receptions for 970 yards and 15 touchdowns.

[8] In 2022, he surpassed Tyler Eifert to become the school's all-time receptions leader at tight end with over 140 catches.

[10] The Las Vegas Raiders selected Mayer with the 35th overall pick in the second round of the 2023 NFL draft.