Abstract The Ordovician succession of the Korean Peninsula is part of the Cambro-Ordovician Joseon Supergroup exposed in the Taebaeksan Basin of South Korea and the Pyeongnam Basin of North Korea. This review summarizes the advances made on these successions over the past two decades, focusing on the Taebaeksan Basin. The Ordovician succession in the Taebaeksan Basin comprises the Taebaek, Yeongwol, Yongtan, Pyeongchang and Mungyeong groups, of which the Taebaek and Yeongwol groups have been studied in detail. These strata are mixed carbonate–siliciclastic deposits formed in peritidal to deep-subtidal environments. Sedimentological and palaeontological studies show that the Korean Ordovician succession represents local variations of the Great Ordovician Biodiversification Event, exemplified by reef evolution, changes in sedimentary systems and changes in invertebrate fossil assemblages. Recent studies of the Yongtan, Pyeongchang and Mungyeong groups have demonstrated that these units are important for understanding the tectonic evolution of the Taebaeksan Basin. The Ordovician strata in the Taebaek Group are generally similar to those of the Pyeongnam Basin and North China; however, the Upper Ordovician–Devonian strata between the two Korean basins show palaeontological affinities to those of South China, perhaps recording the Permo-Triassic collision between the Sino-Korean (North China) and South China blocks.