This chapter explores an intrinsic relationship between colonialism, imperialism, and theories of underdevelopment. The Introduction provides a contextual overview, emphasizing the pivotal role of colonialism in shaping developmental disparities. It elucidates how colonialism, coupled with the expanding role of capitalism, led to severe levels of exploitation, plundering, and famines in colonized regions across Asia, Africa, and Latin America. To illuminate the discourse of underdevelopment, this chapter incorporates the core ideas approached by Marx, Lenin, Baran, Hobson, and Luxemburg and the nature of colonialism with historical evidence. This chapter extensively examines the contributions of key theorists such as. Through a critical review, this chapter offers a nuanced understanding of the relevance and limitations of these theories in explaining underdevelopment. Additionally, a historical analysis traces the impact of colonialism and imperialism on fostering conditions of underdevelopment, providing crucial insights into the enduring legacy of this era.