Cotton is an economically important crop, and, like other agricultural crops, its production has been negatively affected by rapidly changing environments such as extreme heat, water deprivation, salinity, as well as biotic stresses like pathogens and insects. Decades of extensive breeding have employed only a few genotypes for cotton improvement, which has limited identification and deployment of genes that could drastically improve cotton’s tolerance to biotic and abiotic stresses in cotton cultivars in production. Instead, the DNA recombinant technology has successfully generated cotton plants that are more tolerant to biotic and abiotic stresses. Since the emergence of DNA recombinant technology, several methods have been used to introduce foreign genes into cotton. The Bt cotton as the first commercial crop that expresses Bacillus thuringiensis cry genes proved highly effective against lepidopteran insect pests. Since Bt cotton, other transgenic cotton with different traits such as herbicide tolerance have improved cotton production and increased cotton yield. Now with new genomics tools and the development of efficient gene editing technologies, scientists are able to identify genes that can improve cotton’s performance under various biotic and abiotic stress conditions. The introduction and expression of these genes in cotton will benefit management of cotton production and reduce cotton yield loss caused by biotic and abiotic stresses. Here, a summary of cotton transformation technology as well as transgenic cotton with improved agronomic traits is provided.