Rebecca is set mostly on the rural English seaside, some unspecified years before 1938. The setting almost comes alive as a character of its own. The narrator frequently personifies plants and other natural features around Manderley, and it is clear that the place is as much a fixture of her memory as any of the other characters in the story.
While it is not clear exactly what year the events of the novel take place, it is significant that they take place sometime in the 1920s or 1930s. This was a moment in English history between the two World Wars. The first World War, which at this point was known as the Great War, had given people the sense that the world was changing faster than it ever had before. Aristocrats were clinging to the power they still had, but legislation, journalism, and social movements were increasingly making clear that rich and powerful men like Maxim de Winter may not be able to cling to their way of life much longer. Still, the social order had not yet been upended as much as it soon would be by World War II. This was an in-between period, when change seemed to be coming but had not yet reached all corners of England.
Manderley, on the edge of the island country, is a place where change has not fully taken hold yet. The narrator finds herself living in a place with well-established routines, ostentatious landscaping, and old-fashioned architecture she remembers from old pictures of Manderley. It is beautiful, but it is cut off from the hustle and bustle of modern life in places like London. The narrator ends up severely isolated there. While the 1930s were far from a feminist utopia, she winds up in the especially old-fashioned and powerless role of a wife whose husband and neighbors treat her like a child.