In phonetics, a nasal, also called a nasal occlusive, nasal stop, or nasal continuant, is an occlusive consonant produced with a lowered velum, allowing air to escape freely through the nose. Examples of nasals in English are [n] and [m], in words such as nose and mouth. Nasal occlusives are nearly universal in human languages. There are also other kinds of nasal consonants in some languages.

Nearly all nasal consonants are nasal occlusives, where air escapes through the nose but not through the mouth, as it is blocked (occluded) by the lips or tongue. The oral cavity still acts as a resonance chamber for the sound. Rarely, non-occlusive consonants may be nasalized.

Most nasals are voiced, and in fact the nasal sounds [n] and [m] are among the most common sounds cross-linguistically. Voiceless nasals do occur in a few languages, such as Burmese, Welsh and Guaraní. (Compare oral stops, which block off the air completely, and fricatives, which obstruct the air with a narrow channel. Both stops and fricatives are more commonly voiceless than voiced, and are known as obstruents.)