Achomi (Persian: اچُمی), also known as Khodmooni and Larestani, is a Middle Persian (Parsig) derived and Southwestern Iranian language spoken by the Achomi people in southern Fars and western Hormozgan and by significant numbers of Ajam citizens in the UAE, Bahrain, Kuwait, and other neighbouring countries.

It is the predominant language of Gerash, Larestan, Lamerd, Khonj, and Evaz counties in Fars and Bastak County and Ruydar in Hormozgan province.

Moreover, many cities, towns, and villages in Iran have their own particular dialect, such as Larestan, Khonj, Gerash, Evaz, Ashkanan, Bastak, Lar, and Banaruiyeh. The majority of Achomi speakers are Sunni Muslims, with a minority being Shia Muslims.

The Achomi language is considered a descendant of the Sassanid Persian language or Middle Persian.

There are different ways to refer to this language.

Achomi language and its various local dialects such as Lari, Evazi, Khonji, Gerashi, Bastaki, etc... and is a branch of the Middle Persian (Pahlavi) language of the Sassanid Empire.

Today, the language is known as an endangered language. In particular, UNESCO refers to it as a "definitely endangered" language with approximately 1,180,000 speakers. It also does not have official language status in Iran. This is because Iran only recognizes standard Persian as an official language. However, Iran allows the use of minority languages, such as Achomi, in the media and the education system (alongside Persian). Nevertheless, Achomi remains an endangered language with many dialectal differences gradually disappearing because of the domination of Iranian Tehrani New Persian (Farsi).

Many Iranians moved to GCC States in order to pursue better economic opportunities. This included Achomis. These Achomis are often multilingual. Achomi migrants still speak this language in their homes, however, this variety has been influenced by the Arabic language a little but is mutually intelligible with standard Persian.