Dobhashi (Bengali: দোভাষী, دوبھاشي, romanized: Dōbhāṣī, lit. 'Bilingual') is a neologism used to refer to a historical register of the Bengali language which borrowed extensively, in all aspects, from Arabic and Persian. It became the most customary form for composing puthi poetry predominantly using the traditional Bengali alphabet. However, Dobhashi literature was produced in the modified Arabic scripts of Chittagong and Nadia. The standardisation of the modern Bengali language during the colonial period, eventually led to its decline.

No name has been recorded for this register during its development and practice. In the 19th century, an Anglican priest called James Long coined the term Musalmani Bengali, which was also adopted by linguists such as Suniti Kumar Chatterji in the early 20th century. Sukumar Sen referred to it as Muslim Bengali. In 1921, the Islam Darshan monthly published an article on Bengali Muslim literature which referred to the register as Islami Bangla and considered its literature to be the "national literature" of Bengali Muslims. In 1968, Muhammad Abdul Hye and Syed Ali Ahsan published their History of Bengali literature where they coined the name Dobhashi, meaning 'bilingual', which came to be the most popular name for the register. Kazi Abdul Mannan was an advocate for the name Dobashi, as he opines that the register's usage was not limited to Muslims.

Dobhashi Bengali was highly influenced by Arabic and Persian and in poetry, could grammatically change to adapt to Persian grammar without sounding odd to the reader. Arabic and Persian words in the register accounted for the majority of its vocabulary. As in most other foreign languages of Islamic communities, the Arabic borrowings were borrowed through Persian, not through direct exposure of Bengali to Arabic, a fact that is evidenced by the typically Persian phonological mutation of the words of Arabic origin. Dobhashi was also used for forms of story-telling like Puthi, Kissa, Jangnama, Raag, Jari, Hamd, Na`at and Ghazal. Educated Bengalis would be multilingual and multi-literate enabling them to study and engage with Persian, Arabic and Bengali literature. Dobhashi manuscripts are paginated from right to left, imitating the Arabic-tradition.

The following is a sample text in Dobhashi Bengali of Article 1 of the Universal Declaration of Human Rights by the United Nations:

Dobhashi Bengali in the Bengali script

Dobhashi Bengali in a modified Arabic script

دفا ١: تَمام اِنسان آزاد ھَئیا شَمان عِزّت ار حَقّ لئیا پَیدا ھَئي۔ تاهَدير ھوش و عَقل اچھے؛ تائي ايكجَن ارِك جَنير شاتھے بِرادَر حِسابے سُلوك كَرا ضَروري۔

Dobhashi Bengali in phonetic Romanization