The present paper analyzes the novel ‘The Reluctant Fundamentalist’ (2007) from the postcolonial perspective in terms of Cultural Assimilation and Third Space Identity. Postcolonial theory features cultural hybridity and conflictive and conflated identities with a specific focus on theorists like Frantz Fanon’s ‘The Wretched of the Earth’ (1961), Edward Said’s, ‘Orientalism’ (1978) and Homi K. Bhabha’s 8‘Location of Culture’(1994). In the postcolonial context, cultural assimilation refers to cultural domination where the dominant culture seeks to erase indigenous culture and identity, whereas the Third Space Identity is the in-between space where cultural identities are hybridized. In ‘The Reluctant Fundamentalist’ Pakistani expatriate, Changes is filled to the brim with the issue of an identity crisis. After 9/11 he questions his American Dream when he experiences the prejudice of Americans against Muslims. The paper will explore the theme of identity consciousness and crisis that leads to hybridization in the selected text by applying postcolonial theory. The focus of the study will be on Cultural assimilation and Third Space identity and will examine ‘The Reluctant Fundamentalist’ the in pre and post-9/11 literary and socio-political milieu.