In economics and finance, market manipulation is a type of market abuse where there is a deliberate attempt to interfere with the free and fair operation of the market; the most blatant of cases involve creating false or misleading appearances with respect to the price of, or market for, a product, security or commodity.

Market manipulation is prohibited in most countries, in particular, it is prohibited in the United States under Section 9(a)(2) of the Securities Exchange Act of 1934, in the European Union under Article 12 of the Market Abuse Regulation, in Australia under Section 1041A of the Corporations Act 2001, and in Israel under Section 54(a) of the securities act of 1968. In the US, market manipulation is also prohibited for wholesale electricity markets under Section 222 of the Federal Power Act and wholesale natural gas markets under Section 4A of the Natural Gas Act.

The US Securities Exchange Act defines market manipulation as "transactions which create an artificial price or maintain an artificial price for a tradable security".