Green Mansion is a historic home and later commercial building located at Newark in New Castle County, Delaware. It was built about 1882 and is an oblong, three-story, brick building with a flat roofline. It features a green serpentine facade with a two-story bay window at each end, joined in the center by an ornate two-tiered porch featuring paneled columns. It was originally built as a two story residence and expanded in the early 20th century when it began being used for commercial purposes.
It was added to the National Register of Historic Places in 1983.
The building is now used for residential apartments on upper floors and offices on the first floor including a dental office. The building appears to be well maintained and in excellent condition.