The House Democratic leader on Sunday night said "we don't need anyone else around here running the city of Detroit."
Republican Gov. Rick Snyder in March named bankruptcy attorney Kevyn Orr as emergency manager.
Pelosi has served in Congress for a quarter of a century representing a San Francisco district and became the first woman speaker of the House. She praised the work of Detroit Mayor Dave Bing, who on Sunday described the NAACP as a watchdog for fairness.
The event is the largest fundraiser for the Detroit chapter of the National Association for the Advancement of Colored People.