In phonetics, liquids or liquid consonants are a class of consonants consisting of lateral consonants together with rhotics.

Liquids as a class often behave in a similar way in the phonotactics of a language: for example, they often have the greatest freedom in occurring in consonant clusters. In some languages, such as Japanese, there is one liquid phoneme which may have both lateral and rhotic allophones.

English has two liquid phonemes, one lateral, /l/ and one rhotic, /r/, exemplified in the words led and red.

Many other European languages have one lateral and one rhotic phoneme. Some, such as Greek, Italian and Serbo-Croatian, have more than two liquid phonemes. These two languages have the set /l/ /ʎ/ /r/, with two laterals and one rhotic. Similarly, the Iberian languages contrast four liquid phonemes. /l/, /ʎ, /ɾ/, and a fourth phoneme that is an alveolar trill in all but Portuguese, where it is a guttural trill or fricative. Some European languages, like Russian and Irish, contrast a palatalized lateral-rhotic pair with an unpalatalized (or velarized) set (e.g. /lʲ/ /rʲ/ /l/ /r/ in Russian).