Mineral water is water from a mineral spring that contains various minerals, such as salts and sulfur compounds. Mineral water may usually be still or sparkling (carbonated/effervescent) according to the presence or absence of added gases.

Traditionally, mineral waters were used or consumed at their spring sources, often referred to as "taking the waters" or "taking the cure", at places such as spas, baths, or wells. The term spa was used for a place where the water was consumed and bathed in; bath where the water was used primarily for bathing, therapeutics, or recreation; and well where the water was to be consumed.

Today, it is far more common for mineral water to be bottled at the source for distributed consumption. Travelling to the mineral water site for direct access to the water is now uncommon, and in many cases not possible because of exclusive commercial ownership rights. There are more than 4,000 brands of mineral water commercially available worldwide.

In many places the term "mineral water" is colloquially used to mean any bottled carbonated water or soda water, as opposed to tap water.