Conjunct consonants are a type of letters, used for example in Brahmi or Brahmi derived modern scripts such as Balinese, Bengali, Devanagari, Gujarati, Tibetan, Dzongkha etc to write consonant clusters such as /pr/ or /rv/. Although most of the time, letters are formed by using a simple consonant with the inherent value vowel "a" (as with "k" , pronounced "ka" in Brahmi), or by combining a consonant with an vowel in the form of a diacritic (as with "ki" in Brahmi), the usage of conjunct consonant permits the creation of more sophisticated sounds (as with "kya" , formed with the consonants k and y assembled vertically). Conjuncts are often used with loan words. Native words typically use the basic consonant and native speakers know to suppress the vowel.

In modern Devanagari the components of a conjunct are written left to right when possible (when the first consonant has a vertical stem that can be removed at the right), whereas in Brahmi characters are joined vertically downwards.

Some simple examples of conjunct consonants in Devanagari are: त + व = त्व (tva), ण + ढ = ण्ढ (ṇḍha), स + थ = स्थ (stha), where the vertical stroke of the first letter is simply lost in the combination. Sometimes, conjunct consonants are not clearly derived from the letters making up their components: the conjunct for kṣ is क्ष (क् + ष) and for jñ it is ज्ञ (ज् + ञ).

Some examples of conjunct consonants in Gujarati are: પ + ઝ = પ્ઝ (pjha) (where a stroke of the first letter is lost in the combination), હ + ળ = હ્ળ (hḷa), જ + ભ = જ્ભ (jbha). Sometimes, conjunct consonants are not clearly derived from the letters making up their components: the conjunct for śc is શ્ચ (શ્ + ચ) and for ñj it is ઞ્જ (ઞ્ + જ).

Conjunct consonants are used in many other scripts as well, usually derived from the Brahmi script. In Balinese, conjunct consonants are called Haksara Wrehastra.