The snubfin dolphins (Orcaella) are a genus of cetaceans containing two members: the Irrawaddy dolphin (Orcaella brevirostris) and the Australian snubfin dolphin (Orcaella heinsohni). The genus was long believed to be monotypic with the only species being the Irrawaddy dolphin; however, in 2005, supposed Irrawaddy dolphin populations inhabiting the Australian/New Guinean regions were found to be significantly different and were declared a separate new species named the Australian snubfin dolphin.

Until 2005, Orcaella brevirostris was the only recognized species in the genus Orcaella. However, comparisons within the populations of Orcaella inhabiting the Asia region and populations inhabiting the Australia/New Guinea region show distinctions in habitat, morphology, and genetics. Morphological differences include skull shape, presence or absence of a median dorsal groove in front of the dorsal fin, height of dorsal fin, and coloration. Genetic analysis constitutes a 5.9% difference between the two populations. In 2005, these significant distinctions considered by Beasley, Arnold and Robertson warranted a taxonomic split of the genus Orcaella into two separate species, Orcaella brevirostris and Orcaella heinsohni. Orcaella brevirostris known as the Irrawaddy dolphin consists of the Asian population. The newly recognized species, known as the Australian snubfin dolphin, consists of the Australian/New Guinea population.

The snubfin dolphins (Orcaella) contain two of the 35 species of oceanic dolphins that make up the Cetacean family of Delphinidae. The phylogenetic status of Orcaella has long been confused. Although the snubfin dolphins share similar external features with the Monodontidae (narwhal), a genetic study conducted by Arnason and Gretarsdottir identified the 'Irrawaddy dolphin' as a delphinid. In their study, phylogenetic information obtained from a highly repetitive DNA (hrDNA) component characteristic of all cetaceans show that Orcaella share close relationships with the Delphinidae rather than the Monodontidae.

Some molecular analyses indicate that the genus Orcaella is closely related to the orca of the genus Orcinus, the two of them together forming the subfamily Orcininae. However, more recent studies have firmly found that Orcaella belongs in the Globicephalinae.

Irrawaddy dolphins are mainly found in shallow and coastal waters in the Indo-West Pacific region. The Range of their presence stretches from the Bay of Bengal to the northeastern Australian Coast. One of their most common habitats are in the Mekong River of southern Laos, Ranging from the Khone Falls all the way to the Cambodian Border. Much of the data on the Irrawaddy dolphins of this region is collected by the Lao shore, where they are sighted daily during the dry season supposedly due to the importance of deep-water pools in the area. Their geographic range also extends to the coasts of Bangladesh, Myanmar, Thailand, Vietnam, Malaysia, Singapore, and Indonesia with some even being restricted to freshwater environments such as certain bodies of water in India and Thailand. They are known to stay relatively close to the shore, with most sightings being as close 1.6 kilometers off the shoreline and as far as 5 kilometers.

In the western Gulf of Carpentaria in Australia, an estimate of one thousand specimens were calculated, though this number may be incorrect due to the lack of visibility when looking into the water and the unpredictable movement patterns of the dolphins. These dolphins form small groups of around ten, with information leading researchers to believe that they only occur in small, localized populations, rather than large groups that travel together. In spite of this, it is difficult to specifically designate a number for their population due to outstanding factors such as the large lack of data and human interference.

The Irrawaddy dolphin shares similar physical characteristics with the beluga whale, but its genetic makeup ties the Irrawaddy dolphin and the killer whale as close relatives of one another. Irrawaddy dolphins have a slate blue to a slate gray color and their bodies can grow up to 180-275 centimeters in length.

Irrawaddy dolphins eat fish and crustaceans and are rarely found by themselves. They are usually found in groups of around ten dolphins. These dolphins swim rather slowly while scouting for areas. They will raise their heads above the water and continue to swim around to familiarize themselves with their surroundings.