A non-motile, pale yellow, colony-forming strain, designated HME6839(T), was isolated from the wetland of Jeju Island, Republic of Korea. The major fatty acids of strain HME6839(T) were summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 0 and C16 : 1ω5c. The DNA G+C content was 41.2 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain HME6839(T) formed a lineage within the genus Mucilaginibacter. Strain HME6839 (T) [corrected] was closely related to Mucilaginibacter dorajii (96.7 %), Mucilaginibacter polysacchareus (96.5 %) and Mucilaginibacter lappiensis (96.3 %). On the basis of the chemotaxonomic and phylogenetic results presented in this study, strain HME6839(T) represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter flavus sp. nov., is proposed. The type strain is HME6839(T) ( = KCTC 23441(T) = CECT 7857(T)).