White spirit (AU, UK and Ireland) or mineral spirits (US, Canada), also known as mineral turpentine (AU/NZ/ZA), turpentine substitute, and petroleum spirits, is a petroleum-derived clear liquid used as a common organic solvent in painting. There are also terms for specific kinds of white spirit, including Stoddard solvent and solvent naphtha (petroleum). White spirit is often used as a paint thinner, or as a component thereof, though paint thinner is a broader category of solvent. Odorless mineral spirits (OMS) have been refined to remove the more toxic aromatic compounds, and are recommended for applications such as oil painting.

A mixture of aliphatic, open-chain or alicyclic C₇ to C₁₂ hydrocarbons, white spirit is insoluble in water and is used as an extraction solvent, as a cleaning solvent, as a degreasing solvent and as a solvent in aerosols, paints, wood preservatives, lacquers, varnishes, and asphalt products. In western Europe about 60% of the total white spirit consumption is used in paints, lacquers and varnishes. White spirit is the most widely used solvent in the paint industry. In households, white spirit is commonly used to clean paint brushes after use, to clean auto parts and tools, as a starting fluid for charcoal grills, to remove adhesive residue from non-porous surfaces, and many other common tasks.

The word "mineral" in "mineral spirits" or "mineral turpentine" is meant to distinguish it from distilled spirits (alcoholic beverages distilled from fermented biological material) or from true turpentine (distilled tree resin, composed mostly of pinene). This substance is not edible, despite the name "spirits" potentially drawing confusion with liquor, and consumption would result in acute and chronic adverse effects on human health.

Three different types and three different grades of white spirit exist. The type refers to whether the solvent has been subjected to hydrodesulfurization (removal of sulfur) alone (type 1), solvent extraction (type 2) or hydrogenation (type 3).

Each type comprises three grades: low flash grade, regular grade, and high flash grade (flash refers to flash point). The grade is determined by the crude oil used as the starting material and the conditions of distillation.

In addition there is type 0, which is defined as distillation fraction with no further treatment, consisting predominantly of saturated C₉ to C₁₂ hydrocarbons with a boiling range of 140–200 °C (284–392 °F).

Stoddard solvent is a specific mixture of hydrocarbons, typically over 65% C₁₀ or higher hydrocarbons, developed in 1924 by Atlanta dry cleaner W. J. Stoddard and Lloyd E. Jackson of the Mellon Institute of Industrial Research as a less flammable petroleum-based dry cleaning solvent than the petroleum solvents then in use. Dry cleaners began using the result of their work in 1928 and it soon became the predominant dry cleaning solvent in the United States, until the late 1950s.

Turpentine substitute is generally not made to a standard and can have a wider range of components than products marketed as white spirit, which is made to a standard (in the UK, British Standard BS 245, in Germany, DIN 51632). Turpentine substitute can be used for general cleaning but is not recommended for paint thinning as it may adversely affect drying times due to the less volatile components; while it may be used for brush cleaning its heavier components may leave an oily residue.