Lasi, or Lassi, also called Kohistani (Sindhi: لاسي) is a dialect of the Sindhi language spoken on the western frontier of Sindh and Balochistan in Pakistan.

[3][4][5] It is spoken by the Sindhi Lasi people of Lasbela, Hub and Gwadar in Balochistan, and Lasi is also spoken in the Kohistan region of Karachi, Thatta and Jamshoro districts of Sindh.

[6][7] Lasi is known to use loanwords from other languages, primarily from Persian as well as Balochi.

[6] Lasi uses the same orthography as Sindhi except an extra letter, ۏ, which has been added to the Balochi Standard Alphabet.

Many educated Lasi speakers use the Latin alphabet in an effort to romanise the language.