Dan Parris, an assistant superintendent for Fairfax County schools, will serve as the interim deputy superintendent when Richard Moniuszko retires in January.

Parris, who has worked for Fairfax County since 1982, had intended to retire this year but was persuaded to stay and assist the new superintendent, Karen Garza, in her transition. On Thursday, the school board unanimously approved a new contract for Parris, who will retire June 30, 2014.

When Parris first joined the school system in the early 1980s, he worked at Edison High School as a substitute teacher for classes in cosmetology, said Moniuszko. He later taught U.S. history, English and physical education at Carl Sandburg Middle School. He became principal of Rocky Run Middle School in 2003.

For the past three years, Parris has served as assistant superintendent for Cluster 3, responsible for the education of 24,000 students. He oversaw 28 schools in Cluster 3, including the Thomas Jefferson High School for Science and Technology, as well as Annandale, J.E.B. Stuart and Woodson high schools.

A native of Montana, Parris was a graduate of the University of Tennessee, where he served as captain of the rugby team in 1980 and 1981. He later earned a master’s degree in education administration from Virginia Tech.

Parris will serve as a special projects administrator through the summer and fall, assisting Garza as she begins her first school year as superintendent. In January, he will take over as deputy superintendent for Moniuszko, who will retire to teach at George Mason.