He was the founder of Shugart Associates in 1973, later acquired by Xerox. Then he and Finis Conner started Shugart Technology in 1979, which soon changed its name to Seagate Technology.
With Shugart as Chief Executive Officer, Seagate became the world’s largest independent manufacturer of disk drives and related components. In July 1998, Shugart resigned his positions with Seagate.
In 1996 he launched an unsuccessful campaign to elect Ernest, his Bernese Mountain Dog to Congress. Shugart later wrote about that experience in a book, Ernest Goes to Washington (Well, Not Exactly). He backed a failed ballot initiative in 2000 to give California voters the option of choosing "none of the above" in elections.
He is recipient of the 1997 IEEE Reynold B. Johnson Information Storage Systems Award.
Shugart died on December 12, 2006 in Monterey, California of complications from heart surgery he had undergone six weeks earlier.