Genomic evaluation has been successfully implemented in nearly all advanced dairy producing countries. Methods to compute genomic genetic evaluations for dairy cattle can be divided into single-step methods and multi-step methods. This chapter introduces the use of mixed model equations and the numerator relationship matrix, outlining the two basic methods used to compute genomic evaluations. The chapter explains the process of validating methods of computing genomic estimated breeding values. Finally, the chapter examines how genomic selection has changed the dairy cattle industry and looks ahead to future research trends in this area, as well as providing detailed guidance on further reading on the subject.