Praxair, Inc. is an American worldwide industrial gases company. It is the largest industrial gases company in North and South America, and the third-largest worldwide by revenue.

The company was founded by Carl von Linde as Linde Air Products Company in 1907. In 1917, it joined with 4 other chemical companies under the name Union Carbide and Carbon Corporation, while maintaining a separate identity. Its degree of independence waxed and waned over the years, and in 1989, it was spun off as a subsidiary, Union Carbide Industrial Gases Inc., and renamed to Praxair when it became a formally independent company three years later. The name is derived from a combination of the Greek word "praxis", or practical application, and "air", the company's primary raw material.

Praxair was the first company in North America to commercialize cryogenically separated oxygen. The company introduced the first distribution system for liquid gas in 1917 and developed on-site gas supply in the 1940s. In the 1960s, Praxair introduced non-cryogenic means of air separation.

In August 2016 it was publicly announced that the American company was in official negotiations to merger with the German competitor Linde Group, which would form the world's largest gas supplier. The following month in September the negotiations were halted and suspended indefinitely. As of mid December 2016 Praxair has resumed negotiations with Linde for a potential merger In late December an official announcement was made that Praxair has reached an agreement to merger with Linde in a deal valued at $35 billion with an overall merger value of $65 billion. In April, 2017 Linde again rejected a request for a shareholder vote at its annual general meeting in May (from German private-investor association DSW). In May 2017, both companies reached a deal in principle on an all-share merger of equals valued at $75 billion, the deal will still need the approval of Praxair's board of directors as well as Linde's management and executive boards and if approved, will form a new holding company. In early June, both companies agreed to the merger.