Valladay's hometown is Matteson, Illinois and he attended Brother Rice High School.

[2][3] In Wyoming's 2018 season finale, Valladay had a breakout game as he rushed for 192 yards and two touchdowns, as he helped the Cowboys beat New Mexico to become bowl eligible.

[11] For his performance on the year, Valladay was named First Team All Mountain West for the second straight season.

[12] In week nine of the 2021 season, Valladay had another great performance rushing for 172 yards, but Wyoming would fall to San Jose State 27–21.

[15] After the conclusion of the 2021 season, Valladay announced that he had decided to enter the NCAA transfer portal and continue out his career elsewhere.

[20] In week nine, Valladay had another great performance rushing for 118 yards and three touchdowns, as he helped Arizona State take down Colorado.

[24] After not being selected in the 2023 NFL draft, Valladay signed with the Houston Texans as an undrafted free agent.