Porites lobata, known by the common name lobe coral, is a species of stony coral in the family Poritidae. It is found growing on coral reefs in tropical parts of the Indian and Pacific Oceans.

Porites lobata is a hermatypic or reef-building coral. It varies greatly in size and shape depending on its environment. On wave-exposed reef slopes it is encrusting whereas in calm water areas it can grow into large helmet-shaped or hemispherical hummocks up to 6 metres (20 ft) high and wide. Growth rates are very slow, sometimes being as little as 1 centimetre (0.39 in) per year, and this means that large corals are very old. The general colour is greenish, yellow or tan because of the zooxanthellae, single-celled microalgae, that live symbiotically within the tissues. These make organic nutrients available to the polyps through photosynthesis. The corallites are very small and closely packed. They are joined directly to one another by fused but porous walls and have diagnostic skeletal characteristics that are only visible under the microscope.