Button mushrooms (Agaricus bisporus) are a popular and nutritious staple of diets across the globe. Commercial cultivation of the button mushroom begins with a thermophilic composting process in which successive bacterial communities transform starting materials into a specific mushroom growth substrate. One proposed reason for the succession of bacteria is the presence of bacteriophage (phage) in the compost. We have tested the hypothesis that phage populations contribute to mushroom compost through the isolation of phages from compost that are specific to either individual bacterial taxa from compost or well characterised laboratory host bacteria. Isolated phages were tested for their thermal stability and host specificity, whole genome sequenced and observed using transmission electron microscopy. Using compost bacteria as hosts, phages PT226, PT456 and PT816 were isolated using three different strains of the dominant compost species Pseudoxanthomonas taiwanensis and phages PS211 and PS525 were isolated using two strains of Pseudoxanthomonas suwonensis. Phage MC11 infects the laboratory strain Pseudomonas aeruginosa PAO1. Compost phages were morphologically diverse, belonging to both the Myoviridae and Siphoviridae families. All phages were thermostable, maintaining at least 50% infectivity up to 60 °C. Phages PT226 and PS525 were able to infect at least one other compost strain as a host. Phage genomes ranged from 44,718 to 64,720 bp. Phage MC11 belongs to the genus Yuavirus within the Siphoviridae, and Phage PT456 was similar to other Pseudoxanthomonas phages. All other compost phages have no close relatives in the Gen Bank database (<10% coverage), but phages PS211 and PS525 are highly similar to each other (>80% coverage, >97% nucleotide ID). These findings are the first insight into the phage community in mushroom compost and contribute to a larger understanding of the entire compost microbial community.