The Federal Building and Post Office is a historic main post office, courthouse, and Federal office building at 271-301 Cadman Plaza East in the Downtown Brooklyn neighborhood of Brooklyn in New York City. The original building was the Brooklyn General Post Office, and is now the Downtown Brooklyn Station, and the north addition is the courthouse for the United States Bankruptcy Court for the Eastern District of New York, and is across the street from and in the jurisdiction of the main courthouse of the United States District Court for the Eastern District of New York, the Theodore Roosevelt United States Courthouse. It also houses offices for the United States Attorney, In 2009, the United States Congress renamed the building the Conrad B. Duberstein United States Bankruptcy Courthouse, after chief bankruptcy judge Conrad B. Duberstein.

The following properties are listed on the National Register of Historic Places in Brooklyn.