Cat Packer, the former California coordinator for the Drug Policy Alliance, will run the new city division. A five-member Cannabis Commission will provide input on cannabis rules.
The council voted 13-0 to hire Packer, with council members Paul Koretz and Curren Price absent from Wednesday's meeting.
Appearing before the council, Packer said her interest in cannabis policy started after she saw how pot prohibitions and the "war on drugs" disproportionately affected communities of color.
Packer, 26, said the department will protect Los Angeles' neighborhoods, children, the environment and legal cannabis businesses.
"It's extremely important that as this industry develops in the city of Los Angeles, that it's done with consciousness," she said.
Packer's salary still needs to be set by the city. Budget officials allocated $789,800 this fiscal year for the new department, which is expected to have five employees.
The council Wednesday also approved Garcett's nominees to the Cannabis Commission, backing the mayor's picks of Robert Ahn, a former planning commissioner; Rita Villa, a certified public accountant; Philip D. Mercado, regional chief of general surgery at Southern California Permanente Medical Group; Misty Wilks, an attorney; and Victor Narro, a former member of the police commission's Police Permit Review Panel.
Californians voted last year to legalize the recreational use of marijuana and start issuing state licenses by January 2018. The new law comes two decades after the state legalized the use of medical marijuana.
In March, L.A. passed a ballot measure to update its marijuana regulations. That new measure also set tax rates for the cannabis industry, which will provide a new revenue stream for the city.
City Controller Ron Galperin has estimated the city could collect at least $50 million in tax revenue from marijuana businesses next year, based on economic estimates that medical and newly legalized recreational sales citywide could approach $700 million.
A city council committee met Tuesday night to hear input on new rules related to legalization, including where pot shops can operate. Those draft regulations, first released in June, are still evolving, City Council President Herb Wesson said.
11:55 a.m.: This article was updated with the council approving the officials to head the new marijuana department.