Butler County National Bank, also known as the Lafayette Building and Butler Branch Mellon Bank, is a historic bank building located at Butler, Butler County, Pennsylvania. It is located next to the Butler County Courthouse and is considered the first "skyscraper" in Butler. It was built in 1902–1903, and is a six-story, five bay by five bay, brick and stone building in the French Renaissance Revival style. A two-story addition was built in 1929. The front entrance is placed within a curved section at the 90-degree corner facing Diamond Park. The building housed Butler's post office from 1903 to 1913. In 1992–1993, the building was rehabilitated into an apartment building.