Tirhuta (Devanagari: तिरहुता tirhutā; Bengali: তিরহুতা) or Mithilakshar (Devanagari script मिथिलाक्षर mithilākṣar; Bengali alphabet: মিথিলাক্ষর) is the script traditionally used for the Maithili language, an Indo-European language spoken in the Indian state of Bihar, Jharkhand, parts of West Bengal and eastern Nepal. The language has a rich history spanning a thousand years, but years of neglect by the Bihar government and migration have taken their toll on the use of Tirhuta. Most speakers of the language have switched to using the Devanagari script, which is also used to write neighboring Central Indic languages to the west such as Hindi. As a result, the number of people with a working knowledge of Tirhuta has dropped considerably in recent years.

Tirhuta resembles the closely related Bengali Script. In fact, many letters (e.g. ক /k/, খ /kʰ/, দ /d̪/, জ /dʒ/) are written the same in both Tirhuta and Bengali. Nevertheless, there are sufficient differences between the two scripts to somewhat impede mutual comprehension. For example, the letter representing the sound /r/ in Tirhuta has the same form as the Bengali letter ব /b/, and the Bengali letter র /r/ has the same shape as the Tirhuta letter /w/. Furthermore, many of the conjunct letters and vowel signs mean different things in the two scripts. For example, the conjunct ত্ত represents a geminate voiceless unaspirated dental stop /t̪/ in Bengali script, but it represents the syllable /t̪u/ in Mithilakshar.