This special edition of the SOWG e-Newsletter concentrates on Invasive animal and plant species, which are among the largest threats to biodiversity, and are a conservation issue commonly faced across the territories. As such, and inspired by a good deal of interest from SOWG members, this issue will focus exclusively on some of the threats posed by, and efforts to combat, invasive species throughout the Southern Ocean territories. These topics will arise too in UKOTCF’s forthcoming online conference (https://www.ukotcf.org.uk/our-conferences/onlineconference2021/).