Porter has three children from his first wife, Ada Guthrie, now deceased. He and his second wife Joan, who has one child from a previous marriage, have homes in Portola Valley, California and Princeville, Hawaii. Together, the Porters have ten grandchildren. Joan Porter is the founder and president of the Stillheart Institute in Woodside, CA.
In 1999, Porter and his wife Joan gave $25 million to MIT’s Sloan School of Management:
In 2007, the Porters gave 250,000 shares of E-Trade stock to Adams State College (worth approximately $5.8 million at the time), the largest gift in school’s history.
