Campbell's second consecutive term will end in January of 2019.
"It has been a true honor to serve as county superintendent over the past seven years," Campbell said in a statement released by the county education office. "I look forward to continuing to work on behalf of our county's students and their families until a new county superintendent is elected."
Campbell's replaced former superintendent Jean Holbrook in 2010 after Holbrook's retirement and ran unopposed in both the 2010 and 2014 elections.
Candidate Waddell has been with the county education office for 11 years and currently serves as the deputy superintendent of the Instructional Services Division. He has been endorsed by Holbrook as well as a number of other county officials.
"Children and families struggle with the lack of affordable housing, fear of deportation, and threats from Washington, D.C. to essential programs such as Big Lift-funded preschools," Waddell said in his campaign announcement. "The stakes could not be higher."
Prior to serving at the county office, Waddel worked as a principal and counselor at a number of schools as well as an adjunct professor of educational leadership at the graduate level.
The San Mateo County Office of Education oversees the 23 school districts, which includes nearly 94,000 students in the county.