Cliona celata, occasionally called the boring sponge, is a species of demosponge belonging the family Clionaidae. It is found worldwide. This sponge bores round holes up to 5 millimetres (0.20 in) in diameter in limestone or the shells of molluscs, especially oysters. The sponge itself is often visible as a rather featureless yellow or orange lump at the bottom of the hole.

Habitat and geographic range Cliona celata inhabits coastal waters and is known to bore into calcium-rich substrates. They are known to make their home on both living and dead mollusks or other shelled creatures. The also can bore into limestone rocks and various types of corals. They are typically found in waters up to 200 m deep. This sponge is distributed worldwide in the coastal waters of every continent except for Antarctica. They are highly concentrated in the English channel, the North Sea, and the Mediterranean Sea.