Atlantic salmon (Salmo salar) is farmed around the world. To better manage Atlantic salmon farming knowledge of the way bacteria colonise and impact salmon growth and health is needed. In this study the main colonising bacteria of Atlantic salmon farmd in Tasmania (Australia) is defined using 16S rRNA amplicon sequencing, genome sequencing and bioinformatics. Network analysis demonstrates only a few taxa definitively colonise the salmon gut, including Mycoplasmatales, Aliivibrio, Vibrio and Photobacterium. Virtually all other bacteria detected are diet and/or water derived though some may survive intestinal transit. This dataset were obtained from fish collected between 2010 to 2012 over a time course. Sequencing was performed using the 454 pyrosequencing platform and has been published (Zarkasi et al. 2014 and Zarkasi et al. 2016).