| U.S. Post Office, Courthouse, and Customhouse | |
| Location: | 11th and Market Sts., Wilmington, Delaware |
| Coordinates: | 39.7467°N -75.5467°W |
| Built: | 1933-35, 1937 |
| Mapframe: | yes |
| Mapframe-Marker: | building |
| Mapframe-Zoom: | 12 |
| Mapframe-Caption: | Interactive map showing the location of the U.S. Post Office, Courthouse, and Customhouse, Wilmington |
| Architect: | Associated Federal Architects |
| Builder: | Irwin & Leighton |
| Architecture: | Classical Revival |
| Added: | June 14, 1979 |
| Refnum: | 79000638 |
| Nrhp Type2: | indcp |
| Partof: | Rodney Square Historic District |
| Partof Refnum: | 11000522[1] |
| Designated Nrhp Type2: | March 24, 2017 |
| Nocat: | yes |
The U.S. Post Office, Courthouse, and Customhouse, also known as Main Post Office and the Wilmington Trust Headquarters, is a historic post office, courthouse, and custom house, located on Rodney Square in Wilmington, New Castle County, Delaware. It was designed by Irwin & Leighton in 1933–1935, and building was completed in 1937. It is in the Classical Revival. It is a three-story, cut stone structure with six large stone pillars across the main entrance. the gross building area is 104,669 sq. ft.[2] It was listed on the National Register of Historic Places in 1979. A modern Wilmington Trust office building now emerges from the facade.