Dzongkha (རྫོང་ཁ་; Wylie: rdzong-kha, Jong-kă), occasionally Ngalopkha, is the national language of Bhutan. The word "dzongkha" means the language (kha) spoken in the dzong, – dzong being the fortress-like monasteries established throughout Bhutan by Shabdrung Ngawang Namgyal in the 17th century.

"Bhutani" is not another name for Dzongkha, but the name of a Balochi language. The two are sometimes confused, even in some published ISO 639 codelists.

Linguistically, Dzongkha is a South Tibetan language. It is closely related to and partially intelligible with Sikkimese (Wylie: 'Bras-ljongs-skad), the national language of the erstwhile kingdom of Sikkim; and to some other Bhutanese languages such as Cho-cha-na-ca (khyod ca nga ca kha), Brokpa (me rag sag steng 'brog skad), Brokkat (dur gyi 'brog skad), and Lakha (la ka).

Dzongkha bears a close linguistic relationship to J'umowa spoken in the Chumbi valley of Southern Tibet and to the Dranjongke language of Sikkim. It has a much more distant relationship to standard modern Central Tibetan. Although spoken Dzongkha and Tibetan are largely mutually unintelligible, the literary forms of both are both highly influenced by the liturgical (clerical) Classical Tibetan language, known in Bhutan as Chöke, which has been used for centuries by Buddhist monks. Chöke was used as the language of education in Bhutan until the early 1960s when it was replaced by Dzongkha in public schools.