Driscoll replaces Rick Wolford, a director, who has served as interim CEO since February after the previous CEO Michael Mendes was suspended over questionable payments to walnut growers.
Between 2002 and 2007, Driscoll held executive positions at Kraft North America after roles at Nabisco Biscuits, Nestle USA and Procter & Gamble.
Driscoll will bag a base salary of $825,000 in his new role.
Wolford said: "I believe Diamond's future is very bright and will benefit significantly from Brian's experience as the leadership team resumes its industry leadership with the walnut business, executes on its branded snack strategies, and further builds a high performance and productive Company culture."