Many advances in disciplines such as chemistry, biochemistry, plant breeding, genetics, engineering, and others have been applied in a positive manner to improve knowledge in weed science. The emerging field of genomics is likely to have a similar positive effect on our understanding of weeds and their management in various plant agriculture systems. Genomics involves the large-scale use of molecular techniques for identification and functional analysis of complete or nearly complete genomic complements of genes. Commercial application of genomics has already occurred for improvement in certain crop input and output traits, including improved quality characteristics and herbicide and insect resistance. Additional commercial applications of genomics in weed science will be identification of genes involved in a crops' competitive ability. Genes controlling early crop shoot emergence, rapid early-season leaf and root development for fast canopy closure, production of allelochemicals for natural weed control, identification of novel herbicide target sites, resistance mechanisms, and genes for safening crops against specific herbicides can and will be identified. Successful crop improvement in these areas using the tools of genomics will dramatically affect weed–crop interactions and improve crop yields while reducing weed problems. In relation to improved basic knowledge of weeds and the resulting ability to improve our weed management techniques, genomics will offer the weed science community many new and exciting research opportunities. Scientists will be able to determine the genetic composition of weed populations and how it changes over time in relation to agricultural practices. Identification of genes contributing to weediness, perennial growth habit, herbicide resistance, seed and vegetative structure dormancy, plant architecture and morphology, plant reproductive characters (outcrossing and hybridization, introgression), and allelopathy will be identified and utilized with high-throughput DNA sequencing and other genomics-based technologies. Using genomics to improve our understanding of weed biology by determining which genes function to affect the fitness, competitiveness, and adaptation of weeds in agricultural environments will allow the development of improved management strategies. This review provides a summary of the various plant genomic research methods being used. Information is provided concerning the current state of molecular research in various areas of weed science and specific genomic research currently being conducted at Purdue University using transfer DNA (T-DNA) activation tagging to generate large populations of mutated plants that can be screened for genes of importance to weed science.