[7] Founded in 1951 in El Paso, Texas, the company filed for bankruptcy protection in 1990 and went through several owners, before being acquired by Alimentation Couche-Tard in 2003.

Other brands of fuel sold at Circle K stores include Valero, BP, Exxon, Marathon, Irving, Mobil, Esso and Phillips 66.

[1] Circle K operates stores in the United States, Canada, Europe (the Nordics, Baltics, Poland, Russia, & Ireland), and Hong Kong, and has franchises in Mexico (it partners with the Mexican stores "Tiendas Extra" created by Modelo Group), Cambodia, China, Egypt, Guam, Honduras, Indonesia, Jamaica, Macau, New Zealand, Saudi Arabia, South Africa, the United Arab Emirates and Vietnam.

[12][15] The Circle K brand entered the Canadian market in 2008, in connection with Couche-Tard's acquisition of Irving Oil's convenience store network.

[10][3] The rebranding occurred over the following five years; as of March 2020, all of Europe and 85% of North America had been updated with the Circle K brand and logo.

In 1988, the company sent a letter to its over 8,000 employees announcing that it will cut off the medical coverage of those who become sick or injured as a result of AIDS, alcohol, drug abuse or self-inflicted wounds.

"[24] Fortunes declined in the late 1980s as the U.S. economy began to slow down, and Circle K filed for Chapter 11 bankruptcy protection in May 1990; Eller resigned as CEO.

In 2003, Circle K was purchased by Alimentation Couche-Tard, a large, multinational convenience store operator based in the Montreal area,[19] for US$830 million ($1.37 billion in 2023 dollars[23]).

[28] This came after the 2005 rebranding of the various Couche-Tard stores (Mac's, Bigfoot, Dairy Mart, and Handy Andy) under the more nationally known Circle K brand.

In April 2009, ExxonMobil sold 43 Phoenix stores to parent company Couche-Tard as part of a sale of the larger On the Run franchise.

[31] On February 10, 2014, Modelo Group sold the Tiendas Extra brand of stores to the Mexican franchise of Circle K, Circulo K. On December 18, 2014, Couche-Tard announced its acquisition of The Pantry for $860 million all-cash tender ($1.11 billion in 2023 dollars[23]).

[32] Following the closing, all stores that were owned and operated by The Pantry, many of them under the "Kangaroo Express" name, were expected to be rebranded under the Circle K banner.

[citation needed] On September 23, 2015, Couche-Tard unveiled a refreshed brand identity for Circle K, and announced that the Statoil (Northern, Central and Eastern Europe) and Mac's (English Canada) brands would be converted to Circle K.[34][35][36] In 2016, Couche-Tard acquired the Irish service station chain Topaz.

In April 2018, Couche-Tard announced that they too would be rebranded to Circle K.[37] Couche-Tard similarly acquired Imperial Oil's Esso retail locations in Ontario (228) and Quebec (50) the same year, and rebranded the convenience stores in Ontario (many of which previously operated under the On the Run brand) to Circle K.[38] In 2017, Couche-Tard completed its acquisition of CST Brands, adding stores formerly owned by Valero Energy, and a portion of the Ultramar chain in Canada to Circle K (with the latter also switching fuel suppliers to Irving).

[39][40][41] Also in 2017, Couche-Tard bought Holiday Stationstores, a Minnesota-based chain of fuel stations in the Midwestern United States.

[46] In February 2022, Couche-Tard announced that it would rebrand 12 Holiday Stationstores locations in Sioux Falls, South Dakota, to Circle K.[47] In April 2022, The Wall Street Journal reported that Couche-Tard was considering the British convenience store and restaurant operator EG Group, which would have given it a larger presence in Australia, Western Europe, and EG Group's home market of the United Kingdom, as well as the U.S. (where it had bought Kroger's convenience store business, as well as Cumberland Farms), especially in Florida, New England, and Ohio.

[52] A 2021 report on wage theft by the Center for Public Integrity named Circle K as one of the "worst offenders" in the United States.

The Polar Pop was first introduced in Bigfoot convenience stores by Johnson Oil Company in Columbus, Indiana, prior to its acquisition by Alimentation Couche-Tard.