ASH can refer to:

• Austin State Hospital
• Archaic Sealed Heat, a Nintendo game
• Asymmetric septal hypertrophy, a classification for forms of heart disease
• Action on Smoking and Health, opposition to tobacco-smoking
•  Active Session History, a monitoring mechanism within Oracle databases
• Almquist shell, a Unix shell environment
• Anthony Stewart Head, an actor
• alt.suicide.holiday, a Usenet newsgroup

Ash or ashes are the solid remains of fires. Specifically, it refers to all non-aqueous, non-gaseous residues that remains after something is burned. In analytical chemistry, in order to analyse the mineral and metal content of chemical samples,  ash is the non-gaseous, non-liquid residue after a complete 100 ombustion.

Ash is part of Iranian, Azerbaijani, Caucasian, and Turkish cuisine similar to but thicker than soup, which is usually served hot. Depending on the type of ash, it could contain different types of grain, legumes (chick peas, black-eye beans, lentils), vegetables, herbs (parsley, spinach, dill, spring onion ends, coriander, dried mint), onions, oil, meat, garlic, reshteh (in Ash Reshteh) and spices, such as salt, pepper, turmeric, saffron, etc.