The gift has helped the college meet its largest fundraising goal in its 66-year history, college officials said. Roberts' contribution this week pushed the Campaign for Claremont McKenna past $600 million.
"I'm personally thrilled," President Pamela Gann said. "It's amazing to have alumni that so believe in their alma mater and want to support it. It's something our entire community can benefit from."
The college's Board of Trustees will designate a new athletic facility as The Roberts Pavilion in honor of the gift.
Los Angeles-based JFAK Architects designed the three-level, 120,000-square-foot facility that will support the college's co-educational program of 21 varsity sports with an NCAA regulation arena for volleyball and basketball, officials said.
The pavilion, which will replace the 55,000-square-foot Ducey Gymnasium, will also house the Department of Physical Education and Athletics.
Gann said she hopes to have a groundbreaking in 2014 with the facility to be open in 2016.
City officials have signed off on the plan.
Varsity athletics is a big part of the facility, Gann said.
"The two big ones in particular that will play inside the facility are men and women's basketball and women's volleyball," Gann said.
Kristen Dowling, Claremont McKenna's women's basketball coach, said she was looking forward to the opening of the facility.
"It's phenomenal," Dowling said. "I have a great job, but it will help attract better student athletes. This will really help with that."
A cardiovascular and weight fitness center as well as a traditional weight room will be in the facility.
"Those are examples of things to be used by all students," Gann said.
The facility could also be reconstructed as an events center and seats 2,000 people, he said.
"It was very important to have a multi-purpose building," Gann said. "Our event center could hold a group of 2,000 people for a major speaker or a musical event or things like that."
The center, while different than the nearby Marian Miner Cook Athenaeum that hosts speakers every year that range from former presidents to chief executive officers, could be used for certain speakers, Gann said. Former President Bill Clinton drew an overflow crowd when he spoke at the Athenaeum a few years ago, Gann said.
"We have the option of holding a major speaker of that kind in the Roberts pavilion," Gann said.
The facility would also be used by Harvey Mudd College and Scripps College students for sports.
Roberts said Claremont McKenna is a place that continues to grow and excel and it was a privilege to support it.
"We have a great community here. Our student-athletes have the right attitude for both work and play," he said in a news release.
"They deserve a fitness and athletic facility that mirrors the quality of their educational and residential experiences. I am honored that the CMC Board of Trustees has chosen to recognize my unrestricted gift by naming The Roberts Pavilion."
Claremont McKenna is no stranger to receiving large gifts. Officials said in 2007 the campus received a $200 million gift from alumnus Robert Day to create premier training in accounting, economics and finance at the graduate and undergraduate levels.