David Hyon Moon is an American activist, lawyer, and politician. He is currently a member of the Maryland House of Delegates representing District 20 in Montgomery County, Maryland. Since 2023, he has served as the Majority Leader of the Maryland House of Delegates.

The Maryland House of Delegates is the lower house of the legislature of the U.S. state of Maryland. It consists of 141 delegates elected from 47 districts. The House of Delegates Chamber is in the Maryland State House on State Circle in Annapolis. The State House also houses the Maryland State Senate and the offices of the Governor and Lieutenant Governor of the State of Maryland. Each delegate has offices in Annapolis, in the nearby Casper R. Taylor Jr. House Office Building.