The influenza virus has evolved numerous mechanisms to overcome host defenses for its benefit. It can also manipulate the immune system to stop it monitoring and clearing the virus. Small ubiquitin-like modifier (SUMO)ylation is emerging as a key post-translational modification that plays an important part in virus replication. This brief review focuses on recent findings on the roles of SUMOylation during infection by the influenza virus. As such, it will aid understanding of the mechanism of action of infection by the influenza virus, and help to provide new strategies for anti-viral treatment.