ABSTRACTHuman Lyme disease is caused by a number of relatedBorrelia burgdorferisensu lato species. We report here the complete genome sequence ofBorreliasp. isolate SV1 from Finland. This isolate is to date the closest known relative ofB. burgdorferisensu stricto, but it is sufficiently genetically distinct from that species that it and its close relatives warrant its candidacy for new-species status. We suggest that this isolate should be named “Borrelia finlandensis.”