The University of Pennsylvania has received a $225 million gift, the largest in its history, from Raymond G. Perelman and his wife, Ruth, for its medical school, which will be renamed the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania.

“I look at it as Penn Medicine gave me a gift,” Mr. Perelman said. “They offered me an opportunity to have my name on one of the best medical schools in the country.” Mr. Perelman, 93, a trustee of the school, is president and chairman of the board of RGP Holdings Inc., a privately held company with manufacturing, mining and financial interests.

Amy Gutmann, the president of the university, said the Perelmans’ gift was transformational.

“It’s the triple crown for our school of medicine,” she said. “It’s going to enable us to have the best students, with enormously increased financial aid, and to recruit the most eminent faculty and provide extraordinary research.”

The Perelmans’ donation will establish a permanent endowment that will be used, in part, to enable the medical school to increase its financial aid budget by at least 20 percent for the class entering in 2012.