Maryland Route 433 (MD 433) is an unsigned state highway in the U.S. state of Maryland, located in Prince George's County to the northeast of Washington, D.C.

MD 433 begins at an intersection with MD 410 (Veterans Parkway) in New Carrollton in Prince George's County, heading east on four-lane undivided Ellin Road and immediately leaving the city limits.

The route passes through wooded residential areas, curving southeast and then northeast as it becomes a divided highway.

The route narrows to a two-lane undivided road and continues north back into New Carrollton, heading past apartment complexes.

MD 433 runs past businesses before it comes to its terminus at an intersection with MD 450 (Annapolis Road), where 85th Avenue continues north as a municipal road.