Plants host endophytes within their tissues, but much more is known about vascular plant symbioses, while bryophyte symbioses remain poorly understood, especially intracellular associations with bacteria. Vascular plants have complex relationships with the endophytes in their roots where the rhizophagy cycle provides the plant with nutrients sourced from bacteria, especially nitrogen. Bryophytes lack roots but possess many unique structures capable of hosting bacterial endophytes that may contribute nutrients. Pre-existing research on bryophyte-bacteria associations have focused on macroscopic relationships such as epiphytic bacteria, hornwort mucilage cavities, or whole microbiome studies. Here, the presence of nitrogen transfer from bacteria to bryophyte was tested to understand the function of intracellular bacterial endophytes in bryophyte cells. The stem vasculature of mosses and the oil bodies of liverworts consistently host large numbers of bacteria in species across the phylogeny. At both sites sugars are concentrated around the bacterial endophytes, and in the mosses, nitrate is often present surrounding bacterial membranes. The extent of this association is hypothesized to be widespread, with benefits to bryophyte growth. The mechanism governing the regulation of the relationship is likely comparable to the rhizophagy cycle in vascular plants. This is a potential mutualism between bryophytes and their endophytic bacteria, where plant carbon is exchanged for bacterial nitrogen within the plant’s cells. The presence of this relationship in both mosses and liverworts across their respective phylogenies would suggest the mutualism is ancestral to at least the Setaphyta, and perhaps all bryophytes.