Forage species provide the major feed-base for livestock grazing industries supporting production of dairy products, red meat and animal fibres. Because of the complex, multifactorial and highly environmentally sensitive nature of many key breeders’ traits for forage crops, implementation of genomic selection (GS) is a particularly attractive option. Although basic strategies for GS implementation have been devised, forage species display a broad range of biological factors that may influence the precise design of GS-based programs. These factors are described and exemplified by reference to several temperate and warm-season grass and legume species. Current knowledge with respect to such factors, along with the availability of suitable genomic resources and prospects for future activities, is described for several representative species (white clover, tall fescue and phalaris). Generic issues and benefits associated with GS implementation in forage breeding are also assessed.