The promotion is effective February 1.
"After a national search process, I am happy and proud to select our City's next Police Chief from the ranks of the Raleigh Police Department," said Allen in a news release. "I am confident she will both continue and build upon the department's record of public safety effectiveness and community outreach."
Deck-Brown joined the department in 1987. The East Carolina grad is a North Carolina native.
She replaces retired Chief Harry Dolan. Deck-Brown was one of three candidates the city considered. The other candidates were Richmond Police Chief Bryan Norwood, and Malik Aziz, who is a deputy police chief in Dallas, Texas.
Deck-Brown is the first African-American woman to serve as Raleigh's police chief. It is also the first time since 1994 that the city has chosen a chief from within the department's own ranks.