The complete genome sequence of a new virus isolated from a bellflower (Campanula takesimana) plant was determined. The genome of this virus is composed of monopartite single-stranded RNA of 11,649 nucleotides in length. BLAST searches of protein databases showed that the encoded polyprotein has a maximum amino acid sequence identity of 42% (with 99% coverage) to the polyprotein of the isolate Orissa of rice tungro spherical virus (RTSV; genus Waikavirus). Phylogenetic analysis strongly supports that the identified virus is a member of a new species of the genus Waikavirus. The name bellflower vein chlorosis virus (BVCV) is proposed for this new virus.