This comprehensive text integrates particle physics and cosmology, offering a detailed exposé on dark matter. It addresses the historical motivation and observational evidence from galactic dynamics and the Cosmic Microwave Background. The material thoroughly covers early universe phases, including inflation, reheating, and thermal evolution, detailing dark matter production mechanisms like WIMPs and non-thermal origins. Advanced sections focus on computational techniques for predicting direct and indirect detection rates, incorporating crucial galactic halo models.