Bacteriophages, or phages, are viruses that infect bacteria. The interactions between phages and their bacterial hosts are widespread in nature and are not completely understood. In order to infect its host, a bacteriophage must first recognise a specific receptor on the surface of the bacterial cell – the types of receptors on the bacterial cell surface can vary greatly in composition but are specific for a particular phage. We have isolated a novel bacteriophage, YSD1, capable of infecting a variety of different bacterial species of the Enterobacteriaceae family, and have shown that it requires a functional flagellum to infect its host. The genome of YSD1 was sequenced, showing that it is closely related to the bacteriophage Chi, a member of the Siphoviridae family. We have solved the structure of the YSD1 capsid and tail using single-particle cryo-electron microscopy. Negative-stain electron microscopy also revealed that YSD1 has a long thin tail fibre emanating from the end of its tail which targets the flagellum of its host. Immunogold-labelling experiments shows that the long tail fibre is formed by the protein YSD1_29 and that treatment of viable YSD1 with the antibodies that bind YSD1_29 inhibit the phage from infecting Salmonella. Whilst the host range for YSD1 across Salmonella serovars is broad, it is not comprehensive, being limited by antigenic features of the flagellin subunits that make up the Salmonella flagellum. Using phylogenetic and structural analysis of the Flagellin protein, we propose a model for which YSD1 and other Chi-like phages target the flagellum to infect their bacterial hosts.