The genus Sejongia was described in 2005, with the two species Sejongia antarctica and Sejongia jeonii, mainly on the basis of 16S rRNA gene sequence analysis. At that time, these organisms formed a quite separate branch in a 16S rRNA gene sequence-based tree, but, in subsequent studies, it became obvious that the species S. antarctica and S. jeonii and a third species, Sejongia marina, were most closely related (>95.0% similarity) to some Chryseobacterium species (e.g. Chryseobacterium hominis, C. formosense and C. haifense). In addition, there is no evidence for clear phenotypic (i.e. chemotaxonomic) differences between these organisms that justifies their assignment to different genera. For these reasons, a proposal is made to transfer these species to the genus Chryseobacterium as Chryseobacterium antarcticum comb. nov. (type strain AT1013T=JCM 12381T=IMSNU 14040T=KCTC 12225T), Chryseobacterium jeonii comb. nov. (type strain AT1047T=JCM 12382T=IMSNU 14049T=KCTC 12226T) and Chryseobacterium marinum comb. nov. (type strain IMCC3228T=KCCM 42689T=NBRC 103143T) on the basis of 16S rRNA gene sequence data and published phenotypic data.