The school said Thursday that the Williamses initially wanted to keep the May gift anonymous.
"He didn't want those students to miss that experience and wanted to fund those scholarships for next year," athletic director Bubba Cunningham said in a statement. "I still get chills when I think about his phone call and the impact it would have for dozens of our students."
Williams, a Hall of Famer with three NCAA championships, is preparing for his 18th season at his alma mater.
RELATED: Powerful social-justice video by UNC basketball greats began with an idea from Roy Williams
After spring sports were canceled, the NCAA Division I Council approved an extra year of eligibility for all spring sport athletes whose seasons were cut short or canceled because of coronavirus.
The NCAA left it up to individual schools to decide whether to grant spring sport seniors less or equal financial aid for 2021, compared to what they received this past year.
"Roy and Wanda have donated millions of dollars to UNC, the athletic department, the Rams Club and individual sport programs over the years but have always chosen to do so without fanfare or publicity," John Montgomery, executive director of the Rams Club said. "However, we felt this was the proper time to announce our appreciation for all they have done to support their alma mater's academic and athletic pursuits and student-athletes across all 28 of our sports programs, and thank them for an extraordinarily generous contribution to allow our seniors another opportunity at competing in the spring."
RELATED: UNC coach Roy Williams sports a new look, talks COVID-19 concerns