<p>The principle of equality lies at the heart of the Indian constitutional framework. However, the Indian Constitution does not conceive equality as mere formal or arithmetic equality. Instead, it embraces a richer, transformative vision of equality&mdash;substantive equality&mdash;which recognizes historical injustices, structural disadvantages, and social hierarchies embedded in Indian society. Reservation, as a form of affirmative action, is one of the most significant constitutional tools devised to achieve this goal. This article examines reservation as an instrument of substantive equality under the Indian Constitution by analysing its constitutional foundations, philosophical underpinnings, judicial interpretation, and contemporary challenges. It argues that reservation is not an exception to equality but a necessary means to realize genuine equality in a deeply unequal society.</p>