Oilseeds are important crops that contribute to food and nutritional security by supplying essential fatty acids and vital nutrients. Globally, a wide range of biotic and abiotic stresses limits the oilseed production. As these crops are predominantly grown on marginal soils, low nutrient availability poses a major constraint for oilseed production. Oilseed crops require essential nutrients (N, P, K, S) in optimum quantity for proper growth to produce optimum yield. In addition to various agronomic practices, developing crop varieties with improved nutrient use efficiency (NUE) is the most sustainable method. Although conventional breeding approaches have been pivotal in enhancing the yield level of crop plants, improving complex traits such as NUE has been challenging. This chapter discusses the importance of genetic resources and their characterization for utilization in breeding program for improving NUE in oilseed crops. Studies investigating genetic regulation of NUE related traits, detection of genes/QTLs using bi-parental mapping, genome-wide association studies (GWAS), and functional genomics for identifying genes, pathways and regulatory networks involved in NUE related traits have been discussed. Among the advanced genomics-assisted breeding approaches, genomic selection for improving complex traits, such as nutrient use efficiency in oilseed crops, has been reviewed. Furthermore, potent techniques such as CRISPR-based genome editing systems have been discussed in enhancing nutrient use efficiency and nutrient stress tolerance.