The Eosaukia fauna is proposed for the upper Furongian trilobite assemblage from the interval spanning from the upper part of the Hwajeol Formation to the lowermost part of the Dongjeom Formation in the Taebaek Group, Taebaeksan Basin, Korea. It is characterized by the dominance of dikelocephalid trilobites comprising Eosaukia micropora, E. bella, E. acuta, Mictosaukia cf. M. globosa, and Taebaeksaukia spinata n. gen. n. sp. Taxonomic reappraisal of the genus Mictosaukia that has been employed as an upper Cambrian index taxon in eastern Gondwana reveals that more than half of the species of Mictosaukia belong in Eosaukia. This study clarifies the generic concept of Eosaukia, which provides a more reliable biostratigraphic correlation for the upper Furongian strata in eastern Gondwanan regions. The Eosaukia fauna is correlated with the “Mictosaukia” faunas from the upper Fengshanian of North China, upper Taoyuanian of South China, and upper Payntonian of Australia.