The uncertainties of climatic variability and global warming are leading to rising concerns towards ensuring global food security of an expanding population. Unfavorable climatic conditions, like extremes of temperature, drought, flood, and salinity, in addition to the elevated greenhouse gases adversely affect the physiology, and accordingly the quantitative and qualitative characteristics of plants. Mustard (Brassica juncea) and rape (Brassica rapa), the two important oilseed crops of the Indian subcontinent, are also cultivated in Eastern Europe, Russia, China, and Canada. These oilseed crops are affected by various biotic and abiotic stress during different growth and developmental stages, that severely influences agricultural productivity. Extensive breeding efforts toward the development of Brassica cultivars that can resist these climatic variabilities are under various stages of progress. The Brassica germplasm and the wild relatives of B. juncea and B. rapa, which constitute important genetic stocks, are also being utilized in these breeding programs. An integrated approach is required that will study plant-insect pest and disease-climate interactions for conceiving future strategies to develop disease-, insect-resistant, and climate-resilient plant varieties. Developing mustard varieties, efficient in the utilization of soil nutrients, are also required for improving productivity in impoverished soils and for better uptake/utilization of nutrients in soils rich in resources. Future research in oilseed mustard and rape should, therefore, involve examining the influence of climate-smart traits on yield/production in targeted environments, so that climate-resilient cultivars adapted to climate change conditions could be developed. This chapter summarizes the advances in breeding of climate-smart traits such as, tolerance to drought, heat, salinity, flooding and frost, and efficient nutrient utilization, in oilseed mustard and rape, that could assist in the genomic designing for climate-smart crops.