Results of deoxyribonucleic acid homology studies of 116 strains of Veillonella Prévot, representing the two species and seven subspecies currently recognized in this genus, showed seven deoxyribonucleic acid homology groups distinct at the species level. Because the type strains of V. parvula subsp. parvula and V. alcalescens subsp. alcalescens had high homology, we regard V. alcalescens Prévot 1933 as a later subjective synonym of V. parvula (Veillon and Zuber, 1896) Prévot 1933. The species V. parvula, V. dispar (Rogosa) comb. nov., V. atypica (Rogosa) comb. nov., V. rodentium (Rogosa) comb. nov., V. ratti (Rogosa) comb. nov., V. criceti (Rogosa) comb. nov., and V. caviae sp. nov. (type strain, ATCC 33540) are recognized. Because most strains of V. criceti produced acid in peptone-yeast extract-fructose media, the genus description is emended to include strains that ferment fructose.