The Common Hill Myna (Gracula religiosa), sometimes spelled "mynah" and formerly simply known as "Hill Myna", is the myna bird most commonly seen in aviculture, where it is often simply referred to by the latter two names. It is a member of the starling family (Sturnidae), resident in hill regions of South Asia and Southeast Asia. The Sri Lanka Hill Myna, a former subspecies of G. religiosa, is generally accepted as a separate species G. ptilogenys nowadays. The Enggano Hill Myna (G. enganensis) and Nias Hill Myna (G. robusta) are also widely accepted as specifically distinct, and many authors favor treating the Southern Hill Myna (G. r. indica) from the Nilgiris and elsewhere in the Western Ghats of India as a separate species also.
This is a stocky jet-black myna, with bright orange-yellow patches of naked skin and fleshy wattles on the side of its head and nape. At about 29 cm length, it is somewhat larger than the Common Myna (Acridotheres tristis).
It is overall green-glossed black plumage, purple-tinged on the head and neck. There are large white wing patches which are obvious in flight but mostly covered when the bird is sitting. The bill and strong legs are bright yellow, and there are yellow wattles on the nape and under the eye. These differ conspicuously in shape from the naked eye-patch of the Common Myna and Bank Myna (A. ginginianus), and more subtly vary between the different hill mynas from South Asia: in the Common Hill Myna they extend from the eye to the nape, where they join, while the Sri Lanka Hill Myna has a single wattle across the nape and extending a bit towards the eyes. In the Southern Hill Myna, the wattles are separate and curve towards the top of the head. The Nias and Enggano Hill Mynas differ in details of the facial wattles, and size, particularly that of the bill.
Sexes are similar; juveniles have a duller bill.
With the Southern, Nias and Enggano Hill Mynas as separate species, the Common Hill Myna has seven or eight subspecies which differ only slightly. They are:
- Gracula religiosa andamanensis Beavan 1867 – Andaman Hill Myna. Andaman Islands, Central (Nancowry) group of the Nicobar Islands
- Gracula religiosa batuensis – Batu and Mentawai Islands.
- Gracula religiosa halibrecta Oberholser 1926 – Great Nicobar Hill Myna. Great Nicobar Little Nicobar and adjacent islets in the Nicobar Islands. Doubtfully distinct from andamanensis.
- Gracula religiosa intermedia – North-western Indochina and adjacent north-eastern India and southern China.
- Gracula religiosa palawanensis – Palawan in the Philippines.
- Gracula religiosa peninsularis – Bastar Hill Mynah. Central India.
- Gracula religiosa religiosa – Greater Sundas (except Sulawesi) and Peninsular Malaysia.
- Gracula religiosa venerata – Western Lesser Sundas.