The Jinju Formation (), also known as the Dongmyeong Formation () in some literature is an Early Cretaceous geologic formation in South Korea. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. The depositional age of this formation spans from approximately 112.4 ñ 1.3 to 106.5 million years ago (early Albian) based on detrital zircon U-Pb dating. It predominantly consists of black shale, with sandstone packets, deposited in a fluvial-lacustrine setting.
A diverse arthropod fauna, including isopods, spiders, and insects, is known from the formation. Other notable fossils known from the formation include several freshwater fishes, ostracods, and plants. This formation has also "attracted global ichnological attention" for the variety of important ichnofossils. Columnar and rod-shaped stromatolites have also been found here.
Based on plant fossil records, the Jinju Flora is interpreted as a temperate intermontane savannah, due to mountain barriers blocking moisture. The assemblage was dominated by stress-tolerant, low-diversity flora adapted to the arid conditions or to localized waterlogged niches. Not only restricted to the Jinju Formation, but the entire floral diversity was relatively low throughout the entire Gyeongsang Supergroup. Palynofossil records also suggest the Jinju Formation was overall arid
Unnamed plant remains include 3 different types of unidentified ferns, at least 2 types of seed cones, a conifer pollen cone, detached conifer seed cone scales, a connate bractate organ of unknown affinity, and at least 9 different types of diaspores, including winged forms and likely fleshy forms.
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Unnamed ichnofossils from the Jinju Formation include Ornithopod tracks and Caddisfly bioherms.