Phillips 66 is a brand of gasoline and service station in the U.S. It is owned by the Phillips 66 Company.

Phillips 66 is also the name of the downstream company created when ConocoPhillips repositioned its integrated assets and businesses into two independent, publicly traded companies as of May 1, 2012. Phillips 66 Company has leading businesses in refining, marketing, midstream and chemicals. It is led by Greg C. Garland, Chairman and CEO.

The company that makes Phillips 66 gasoline began in 1917 as Phillips Petroleum Company, founded by L.E. Phillips and Frank Phillips of Bartlesville, Oklahoma. In 1927, the company's gasoline was being tested on U.S. Highway 66 in Oklahoma, and when it turned out that the car was going 66 mph (106 km/h), which was fast at the time, cementing the idea of "66", which was originally disliked, the company decided to name the new fuel Phillips 66.

The first Phillips 66 service station opened November 19, 1927, in Wichita, Kansas. The first station to be built in Texas was built in 1929 at McLean. Both of these stations have been preserved by local historical societies.