A Gram-negative, short-rod-shaped, orange-pigmented bacterium, strain LYYY01(T), was isolated from a mangrove sediment sample collected from Yunxiao mangrove National Nature Reserve, Fujian Province, China. 16S rRNA gene sequence comparisons showed that strain LYYY01(T) is a member of the family Flavobacteriaceae, forming a distinct lineage with species of the genera Meridianimaribacter, Sediminibacter, Gelidibacter and Subsaximicrobium. The 16S rRNA gene sequence similarity between strain LYYY01(T) and the type strains of related species ranged from 93.9 to 90.9%. Growth was observed at temperatures from 10 to 38 °C, at salinities from 1 to 7% and at pH from 6 to 10. The DNA G+C content of the strain was 38.6 mol% and the major respiratory quinone was menaquinone-6 (MK-6). The major fatty acids were iso-C15:1 (27.6%), iso-C15:0 (24.0%), iso-C17:0 3-OH (12.0%) and iso-C16:0 3-OH (6.2%). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, strain LYYY01(T) is considered to represent a novel species of a new genus in the family Flavobacteriaceae, for which the name Mangrovimonas yunxiaonensis gen. nov., sp. nov. is proposed. The type strain of Mangrovimonas yunxiaonensis is LYYY01(T) (=CGMCC 1.12280(T)=LMG 27142(T)).