Shugart helped pioneer the multibillion-dollar hard drive industry, in which Seagate now holds the leading market position. He founded the company in 1979 and left in 1998.
Described by some as a maverick, Shugart was well-known for his colorful personality that included an effort to get his dog to run for Congress. The unsuccessful ploy became the topic of one of his three books, "Ernest Goes to Washington (Well, Not Exactly)."
Shugart died Tuesday at Community Hospital of the Monterey Peninsula, said Seagate spokeswoman Julie Stills. He was admitted last week and died of complications from heart surgery he underwent six weeks ago.
He was still working until the day of his death, checking e-mails for his company, Al Shugart International, a startup incubator based in Santa Cruz, Stills said.
He is survived by his wife, Rita, four daughters, a son, and seven grandchildren.