The Sidney M. Aronovitz United States Courthouse is a courthouse of the United States located in Key West, Florida. Built in 1932 and opened the following year, the courthouse replaced the Old Post Office and Customshouse in providing access to the United States District Court for the Southern District of Florida for residents of Monroe County, Florida. The building was originally named the U.S. Post Office, Custom House, and Courthouse. In October 2009, President Barack Obama signed into a law a bill introduced by Representative Ileana Ros-Lehtinen to rename the building for former longtime District Court judge Sidney M. Aronovitz, a third-generation Key West native.