Post-colonialism is a literary theory designed to explore the works of authors from countries that were once part of the British Empire. After gaining independence, the citizens of these nations have had to grapple with their identities as educated British subjects while being aware of their past subjugation by the British government. This awareness has been heightened by their newfound self-governance. This theme is reflected in Annie's connection to Jane Eyre and her references to Milton and Shakespeare. Annie has been educated in English literature—the stories originating from the land of her former colonizers. Yet, instead of rejecting this literature, the post-colonial writer embraces it, using the English language to tell her own distinct story.

The novel Annie John is rich with references to the history of colonialism, notably in two key instances involving a classmate named Ruth and the figure of Christopher Columbus. These events occur in Chapter 5, "Columbus in Chains," but their influence resonates throughout the entire narrative. As a diligent student, Annie wrestles with reconciling her heritage and determining her place "with the masters or the slaves—for it was all history, it was all in the past, and everyone behaves differently now." However, memories and emotions tied to the past persist. Annie reflects on Ruth, observing, "Perhaps she wanted to be in England, where no one would remind her [what] her ancestors had done."

A crucial element of Annie's self-awareness as a postcolonial individual is her defiance against historical narratives. She is caught not paying attention during a history lesson and is punished for defacing her textbook in a disrespectful manner. "I had gone too far this time," she admits, "defaming one of the great men in history, Christopher Columbus, discoverer of the island that was my home." Annie recognizes the fragile concept of the island being her home. She exists there as an unusual result of Empire, yet it is her home, much like English culture is hers, albeit with a hint of obeah.