In 1963, Timothy P. O'Donnell founded O'Donnell Associates in Northern California. Several years later, Mr. O'Donnell moved to Southern California to continue the operation from there. At the time, the Aerospace business was very strong and Southern California was the dominant territory serving this important market segment.

In 1972, Mr. O'Donnell incorporated three different companies, one in Northern California, one in Southern California, and one in Phoenix, Arizona. Realizing that his company had grown significantly, and that each of his three operations was substantively different from one another, creating three separate companies made sense.

In 1979, Mark Conley joined the Northern California operation after leaving Sperry Univac Corporation.

In 1986, O'Donnell North acquired Abbott Engineering. With the acquisition of Abbott, came Jay Abbott. Immediately following the acquisition of Abbott Engineering, Mark and Jay began the process of purchasing O'Donnell Associates North, Inc. from Timothy O'Donnell and Cliff Bird.

In 1991, the acquisition of O'Donnell North was completed. In the same time frame, Timothy O'Donnell sold his two other rep firms to employees located in the respective companies (Phoenix and Southern California). At this time, the three rep companies had no further common ownership whatsoever.

In 2006, Charlie Brenner, employee since 1986, became a full partner in the firm.

O'Donnell North continues to grow on average, 15% per year. Today the company employs 11 individuals and is located in the heart of Silicon Valley, five minutes from San Jose International Airport.