Bílinská kyselka (in English: Biliner, Bílina acidulous water) is strongly mineralized alkaline bicarbonate (i.e. 5 to 7 grams per litre) mineral water from Bílina city (Czech Republic).

Particularly sodium, potassium, calcium, magnesium, and iron are present as cations, as are anions of chloride, sulfate, and bicarbonate.

Water is collected from a borehole from a depth of 191 m under the mountain Bořeň.

Biliner bottles are cobalt blue polyethylene terephthalate.

The authors of the first scientific publications were balneologists Franz Ambrosius Reuss, August Emanuel von Reuss, and Josef von Löschner.