United States post offices operate under the authority of the United States Post Office Department (1792–1971) or the United States Postal Service (since 1971). Historically, post offices were usually placed in a prominent location. Many were architecturally distinctive, including notable buildings featuring Beaux-Arts, Art Deco, and Vernacular architecture. However, modern U.S. post offices were generally designed for functionality rather than architectural style.

Following is a list of United States post offices in the territories of the United States. Notable post offices include individual buildings, whether still in service or not, which have architectural, historical, or community-related significance. Many of these are listed on the National Register of Historic Places (NRHP) or state and local historic registers.

Puerto Rico Post officeCityDate builtImageArchitectNotesMiguel Angel García Méndez Post Office BuildingMayagüez1935Louis A. Simon, Neal A. MelickLuis A. Ferré United States Courthouse and Post Office BuildingPonce1933James A. WetmoreHistory of the Federal Judiciary: Historic Federal Courthouses: Ponce, Puerto Rico. Retrieved 23 May 2013.U.S. Post Office and Courthouse, now Jose V. Toledo Federal Building and United States CourthouseSan Juan1911–1914James Knox Taylor, Louis A. Simon United States Virgin Islands Post officeCityDate builtImageArchitectNotesAlvardo de Lugo Post OfficeCharlotte Amalie, St. Thomas1937–1938Louis A. Simon, Neal A. Melick Notes

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