As a proven source of potent and selective antimicrobials,Xenorhabdusbacteria are important to an age plagued with difficult-to-treat microbial infections. Yet, only 27 species have been described to date. In this study, a novelXenorhabdusspecies was discovered through genomic studies on three isolates from Kenyan soils. Soils in Western Kenya were surveyed for steinernematids andSteinernemaisolates VH1 and BG5 were recovered from red volcanic loam soils from cultivated land in Vihiga and clay soils from riverine land in Bungoma respectively. From the two nematode isolates,Xenorhabdussp. BG5 andXenorhabdussp. VH1 were isolated. The genomes of these two, plus that ofX. griffiniaeXN45 – this was previously isolated fromSteinernemasp. scarpo that also originated from Kenyan soils – were sequenced and assembled. Nascent genome assemblies of the three isolates were of good quality with over 70 % of their proteome having known functions. These three isolates formed theX. griffiniaeclade in a phylogenomic reconstruction of the genus. Their species were delineated using three overall genome relatedness indices: an unnamed species of the genus,Xenorhabdussp. BG5,X. griffiniaeVH1 andX. griffiniaeXN45. A pangenome analysis of this clade revealed that over 70 % of species-specific genes encoded unknown functions. Transposases were linked to genomic islands inXenorhabdussp. BG5. Thus, overall genome-related indices sufficiently delineated species of two newXenorhabdusisolates from Kenya, both of which were closely related toX. griffiniae. The functions encoded by most species-specific genes in theX. griffiniaeclade remain unknown.