The preferred walk-on will head to Campbell with three years of eligibility remaining.
Leon will enter the role following former head coach Greg Nye's retirement after 31 years.
The nation's leading female Divison I goal scorer from the 2022 season is heading to Happy Valley.
Dunn will arrive in Happy Valley with two years of eligibility remaining.
"It was imperative for these two powerful collectives to join forces to provide a large breadth of NIL opportunities for student-athletes in all 31 of our sports programs to continue to push us forward."
The 13 student-athletes traveling to this season's championships mark the largest showing of Nittany Lions since 2017.