Castello Brown is a historic house museum located high above the harbour of Portofino, Italy. Its site has been used for military defence since Roman times. As a Genoese coastal fort, it was called the Castello di San Giorgio. After peace fell upon the region in the early 19th century, the Castello was abandoned. Some decades later, it was purchased by the English consul, who remodelled it as a comfortable villa. His descendants held the property until 1949, then sold it to an English couple who restored several ruined sections, and in turn sold it in 1961 to the City of Portofino, which now opens it to the public.
Elizabeth von Arnim wrote and set her novel The Enchanted April at the Castello in 1922. The award-winning 1991 movie adaptation featuring Miranda Richardson and Joan Plowright was filmed on site.