Born in Boston, Joseph DiGirolamo's study at Purdue was interrupted by three years of service in the Navy as an Electronic Technician First Class. After World War II, he returned to Purdue where he completed his BSEE degree in 1948.

Upon graduation, he took a position as a relay and controls engineer with Indiana and Michigan Co. In 1953, he moved to CTS Corporation to become a production project, design and development engineer. During the next 32 years of his career, DiGirolamo remained with CTS, rising steadily to become chairman of the board and chief operating officer of CTS Corporation.

The holder of ten patents, DiGirolamo has served on numerous corporate and civic boards including that of the Indiana State Chamber of Commerce and the Elkhart Chamber of Commerce. He is presently a trustee of the CTS Foundation, a director of the Purdue Research Foundation, and is on the board of directors of the Better Business Bureau. DiGirolamo was named a Purdue Distinguished Engineering Alumnus in 1983, participated in the Old Masters Program at Purdue in 1984, and was awarded an honorary doctorate in 1985.