The Tenjong Dendang Formation is a geologic formation in Malaysia. The band of graptolite- and trilobite-bearing shales interbedded in limestones preserves graptolite, brachiopod and trilobite fossils dating back to the Hirnantian stage of the Late Ordovician period. The sediments were deposited during the Late Ordovician glaciation.

The following fossils were reported from the formation:

• Mucronaspis mucronata
• ?Stenopareia sp.

• Hyolithida indet.

• Plectambonitoidea indet.

• Lophospira sp.
• ?Megalomphala sp.

• Climacograptus sp.

• Kobayashi, T.; Jones, C. R.; Hamada, T. (1964), "On the Lower Silurian shelly fauna in the Langkawi Islands, Northwest Malaya", Japanese Journal of Geology and Geography, 35: 73–80