Ellis was the second Nittany Lion to sign a UDFA after Curtis Jacobs signed with Kansas City.
Jacobs will join Hunter Nourzad, who was a fifth-round selection, with the Chiefs.
A poor showing against Ohio State started a downward trend for the once-first-round projection.
Hardy became the seventh Penn State defensive back to hear his name called.
The group spent an hour protesting in front of Old Main after marching through the streets of Penn State and downtown State College.
Penn State will play Maryland in the next round in Columbus.