Marchen, also called the Greater Mar or the Greater Beautiful script, is one of a group of related scripts used in the Tibetan Bön religion. It is used for writing the Zhang-zhung language, now preserved only in Bön literature, and occasionally for writing Tibetan. This script is not to be confused with the Marchung script, a related but separate script about which little is known beyond that it has been used in some other Bön texts.

Marchen writing employs similar principles to Tibetan; each consonant has a base form and a subjoined form which can be combined in vertical stacks to represent consonant clusters. There are also five vowel signs which can be attached to a base consonant or to a consonant stack; in the absence of one of these signs, consonants have an inherent /a/ vowel.