The poultry industry currently accounts for the production of around 118 million metric tons of meat and around 74 million metric tons of eggs annually. As the global population continues to increase, so does our reliance on poultry as a food source. It is therefore of vital importance that we safeguard this valuable resource and make the industry as economically competitive as possible. Avian viral infections, however, continue to cost the poultry industry billions of dollars annually. This can be in terms of vaccination costs, loss of birds and decreased production. With a view to improving the health and welfare of commercial birds and to minimizing associated economic losses, it is therefore of great importance that we try to understand the genetic mechanisms underlying host susceptibility and resilience to some of the major viral pathogens that threaten the poultry species. Some avian viruses, through their zoonotic potential, also pose a risk to human health. This Special Issue will present papers that describe our current knowledge on host responses to various viral pathogens, the genetics underlying those responses and how genomics can begin to provide a solution for resolving the threat posed by these infections.