Dana Williamson will assume the position, to which other agency secretaries traditionally report.
Brown, a Democrat, oversees an unusually flat administration, announcing when he took office in 2011 he would not employ a cabinet secretary. At the time, Brown said his decision was part of an effort to reduce annual spending in the governor's office.
Brown has declined to name a chief of staff, though Nancy McFadden, an executive secretary, performs the duties of one.
Williamson, 41, has been a senior adviser to Brown since 2011. Williamson, a Democrat who worked previously as director of public affairs at Pacific Gas and Electric Co., will be paid $160,008 a year.
Her appointment was one of seven announced late this afternoon.
Wade Crowfoot, deputy director at the Governor's Office of Planning and Research since 2011, has been appointed deputy cabinet secretary and senior adviser to Brown. The 40-year-old Democrat will be paid $142,008 a year.
Brown named Joginder Dhillon senior adviser for tribal negotiations, Daniel Powell deputy legal affairs secretary and Julie Lee director of operations.
In the governor's communication's office, Brown named Jim Evans chief deputy press secretary and James Lynch communications deputy.
PHOTO: Gov. Jerry Brown speaks at the California State Prayer Breakfast in Sacramento on Thursday, May 19, 2011. The Sacramento Bee/Randy Pench