With the rising global demand for food, animal feed, and industrial raw materials and to fulfil this demand, there is an urgent requirement for crop improvement. However, challenges such as shrinking arable land, water scarcity, and the effects of climate change limit the effectiveness of conventional farming approaches. To overcome these obstacles and ensure food security, it is essential to adopt innovative strategies that enhance crop yield, quality, and resilience to different stresses. Mutation breeding has become an effective method in crop improvement programs to increase yield and improve grain quality. The chapter provides an in-depth exploration of mutation breeding with a special focus on cereal crops, particularly wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). Application of physical and chemical mutagens has enabled the development of novel genetic variations that are otherwise rare in natural populations. Induced mutations have been very helpful in improving important plant traits like plant height, grain size, stress resistance, and nutritional value. A comprehensive overview of the role of mutation breeding in increasing yield and quality traits in wheat and barley is presented. In addition, traditional mutation breeding has significantly increased the accuracy and speed of identifying beneficial mutants. Using wheat and barley as a representative cereal crop, the chapter highlights the practical significance and future potential of mutation breeding in ensuring food security and advancing sustainable agriculture.