The Toyota Prius (pron-en?pri??s) is a full (Hybrid vehicle drivetrain#Full Hybrids) hybrid electric (hybrid electric vehicle) mid-size car developed and manufactured by the Toyota Motor Corporation. The Prius is the most fuel efficient gasoline car currently sold in the U.S. according to the United States Environmental Protection Agency. The EPA and California Air Resources Board (CARB) also rate the Prius as among the cleanest vehicles sold in the United States based on smog forming and toxic emissions (Motor vehicle emissions).

The Prius first went on sale in Japan in 1997, making it the first mass-produced hybrid vehicle. It was subsequently introduced worldwide in 2001. The Prius is sold in more than 40 countries and regions, with its largest markets being those of Japan and North America.cite press releaseurl=title=Worldwide Prius Sales Top 1 Million publisher=Toyota Motor Corporation date=2008-05-15 accessdate=2008-05-29 In May 2008, global cumulative Prius sales reached the milestone 1 million vehicle mark, and by early 2010, the Prius reached worldwide cumulative sales of 1.6 million units. As the global top seller market, the U.S. made up more than half the Prius sold worldwide, with 814,173 units registered by December 2009.