In 1994, while still working in the Wilson Administration, Marin ran for a city council seat in Huntington Park and won. She served seven years on the council, including a term as mayor from 1999 to 2000 – the first Hispanic to hold that post in the city's history. During her tenure, Marin was known as a law-and-order politician and was credited with various public safety initiatives that reformed the police department, increased its funding, and reduced crime by 50%. She also instituted a task force to combat air pollution in response to a government study that listed Huntington Park as one of several communities particularly at risk and launched a crackdown on a black market for illegal documentation. Despite her political registration, Marin was overwhelmingly re-elected to the council in 1999.