Tomato (Solanum lycopersicum L.) is an excellent plant model for unravelling physiological processes, fruit quality and shelf-life determinants, such as stress-responsive signalling, pathogenicity and ripening in climacteric fruits. Consumer awareness of tomato as a phytonutrient source of lycopene, β-carotene, flavonoids and vitamin C has intensified tomato research. The genome of inbred tomato Heinz 1706 cultivar has already been deciphered, genetic linkages for fruit quality have been characterized and tomatoes have been genetically engineered to enhance fruit quality and abiotic/biotic stress tolerance. Furthermore, tomato is a model for vaccine production. This chapter shows how genetic dissection using fruit-ripening mutants, new transgenic plants and molecular breeding has created a road map for the further unravelling of the regulation of genes governing fruit quality attributes as well as fundamental metabolic processes. Precision in engineering plant genomes has enabled development of novel tomatoes with marketable traits beneficial to human health.