Cereus Blooms at Night takes place on the fictional island of Lantanacamara, but it is commonly understood that this setting is based on the real island of Trinidad, where the author, Shani Mootoo, grew up. Trinidad (of the nation of Trinidad and Tobago) is part of the West Indies chain of islands in the southern Caribbean and has a complex colonial and racial history. Originally colonized by Spain, it was settled by Spanish and French landowners before becoming part of the British Empire in 1802.

In addition to native Trinidadians being colonial subjects, the imperial powers brought enslaved people from Africa to the island. When slavery was outlawed in 1838, the British created a system of indentured labor using subjects from their colonies in Asia, most notably India. Descendants of these Africans and Indians remained on the island even after the nation gained its independence in 1962. As such, Trinidadian society still contains influences from all three colonial powers, combined with indigenous, African, and Indian cultures, creating a thoroughly creolized culture, language, and traditions. The fictional setting of Lantanacamara evokes Trinidad in its lush tropical depiction, as well as in the unique dialect spoken by its characters and their racial, sometimes multiracial, identities.