The Indo-Pacific bottlenose dolphin (Tursiops aduncus) is a species of bottlenose dolphin. This dolphin grows to 2.6 m (8.5 ft) long, and weighs up to 230 kg (510 lb). It lives in the waters around India, northern Australia, South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its belly is lighter grey or nearly white with grey spots.

The Indo-Pacific bottlenose dolphin is generally smaller than the common bottlenose dolphin, has a proportionately longer rostrum, and has spots on its belly and lower sides. It also has more teeth than the common bottlenose dolphin — 23 to 29 teeth on each side of each jaw compared to 21 to 24 for the common bottlenose dolphin.

Much of the old scientific data in the field combine data about the Indo-Pacific bottlenose dolphin and the common bottlenose dolphin into a single group, making it effectively useless in determining the structural differences between the two species. The IUCN lists the Indo-Pacific bottlenose dolphin as "near threatened" in their Red List of endangered species.

Until 1998, all bottlenose dolphins were considered members of the single species T. truncatus. But in that year, the Indo-Pacific bottlenose dolphin was recognized as a separate species. Both species are thought to have split during the mid-Pleistocene, about 1 million years ago.

Some evidence shows the Indo-Pacific bottlenose dolphin may actually be more closely related to certain dolphin species in the genera Stenella and Delphinus, especially the Atlantic spotted dolphin (S. frontalis), than it is to the common bottlenose dolphin. However, more recent studies indicate that this is a consequence of reticulate evolution (such as past hybridization between Stenella and ancestral Tursiops) and incomplete lineage sorting, and thus support T. truncatus and T. aduncus belonging to the same genus.

The Burrunan dolphin (T. (aduncus) australis) has been alternately considered its own species, a subspecies of T. truncatus, or a subspecies of T. aduncus. Following the results of a 2020 study, the American Society of Mammalogists presently classifies it as a subspecies of T. aduncus. The same study delineated 3 distinct lineages within T. aduncus which could each be their own subspecies: an Indian Ocean lineage, an Australasian lineage, and the Burrunan dolphin. The Society for Marine Mammalogy does not recognize the Burrunan dolphin as a distinct species or subspecies, citing the need for further research.

Indo-Pacific bottlenose dolphins are very similar to common bottlenose dolphins in appearance. Common bottlenose dolphins have a reasonably strong body, moderate-length beak, and tall, curved dorsal fins; whereas Indo-Pacific bottlenose dolphins have a more slender body build and their beak is longer and more slender. The Indo-Pacific population also tends to have a somewhat lighter blue colour and the cape is generally more distinct, with a light spinal blaze extending to below the dorsal fin. However, although not always present, the most obvious distinction can be made with the presence of black spots or flecks on the bellies of adults of Indo-Pacific bottlenose dolphins, which are very rare in common bottlenose dolphins. Their teeth can number between 23 and 29 in each upper and lower jaw, and are more slender than those of common bottlenose dolphins. Size of Indo-Pacific bottlenose dolphins can vary based on geographic location; however, its average length is 2.6 m (8.5 ft) long, and it weighs up to 230 kg (510 lb). The length at birth is between 0.84 and 1.5 m (2.8 and 4.9 ft).

The local population centering Mikura-jima is claimed to be a distinct form or species.