The airline focuses on serving leisure traffic from small and medium-sized cities which it considers to be underserved, using an ultra low-cost business model with minimal inclusions in fares and a greater number of add-on fees.

Allegiant Air was founded in January 1997 by Mitch Allee (owner, CEO), Jim Patterson (president), and Capt.

[1] After losing a trademark dispute with Westjet Air Center of Rapid City, South Dakota, and recognizing the name's similarity to WestJet Airlines of Calgary, Alberta, the airline adopted the name Allegiant Air and received FAA and US DOT certification for scheduled and charter domestic operations on June 19, 1998.

[7] Later in 2000, Allegiant continued to expand and was operating the only nonstop jet service between Lake Tahoe Airport and Long Beach Airport in addition to operating new flights into Portland, Oregon and Reno with Portland-Reno and Reno-Fresno nonstops and direct one-stop service between Portland and Fresno via Reno.

[8] Citing higher fuel costs as a major factor, Allegiant filed for Chapter 11 bankruptcy protection in 2000.

In June 2001, Gallagher restructured Allegiant to a low-cost model, focusing on smaller markets that larger airlines did not serve with mainline aircraft.

[11] In March 2002, Allegiant entered into a long-term contract with Harrah's to provide charter services to its casinos in Laughlin and Reno, Nevada.

By 2004, Allegiant was flying from 13 small cities to Las Vegas and offering bundled air and hotel packages.

In May 2005, the airline's holding company, Allegiant Travel, completed a private equity placement worth $39.5 million.

[13] In November 2006, Allegiant filed a registration statement with the Securities and Exchange Commission in anticipation of a planned initial public offering of its common stock.

[16] In February 2010, Allegiant opened its ninth base at Grand Rapids' Gerald R. Ford International Airport in Michigan.

[21] In March 2010, Allegiant purchased six used Boeing 757-200 jetliners as part of plans to begin flights to Hawaii, with deliveries from early 2010 to the fourth quarter of 2011.

"Before the night was finished on June 25, 2015, five Allegiant flights had been interrupted in four hours, all because different planes had failed in midair," reported the Tampa Bay Times.

In January 2019, Allegiant announced that it would be adding another base at Gerald R. Ford International Airport in Grand Rapids, Michigan.

[31] On February 12, 2021, Allegiant launched flights to John Wayne Airport with 8 initial destinations including Boise, Grand Junction, Las Vegas, Medford, Missoula, Provo, Reno/Tahoe, and Spokane.

[33] On October 7, 2021, Allegiant began serving non-stop flights from Minneapolis-St. Paul International Airport to Asheville, North Carolina, and Palm Beach, Florida.

[35] Allegiant aims primarily to serve leisure travelers, particularly those from colder northern climates going to warm-weather tourist destinations such as Punta Gorda, Tampa, Las Vegas, Orlando, Los Angeles, and Phoenix.

[10][41] The company also prefers to use secondary airports when those facilities charge smaller fees, such as Orlando Sanford, MidAmerica St. Louis, and Phoenix–Mesa, where Allegiant is the only commercial carrier with year-round service.

Many of its customers at airports such as Bellingham, Washington and Plattsburgh, New York are Canadians, who save money on airfare by crossing the border to the U.S. and flying domestic routes from U.S.

[10] Allegiant schedules their crew members so that they typically return to their home base at the end of the day, avoiding the expense of hotel rooms.

"[46] Allegiant also earns commissions by offering hotel rooms, car rentals and admission to tourist attractions on its website.

[50] Allegiant based one 150-seat, MD-80 jet aircraft in Wendover and more than 20 employees, including maintenance, flight crews and station personnel.

[59] Allegiant Air's livery features a bright sunburst design on the tail, emphasizing the airline's "sun" destinations.

ABC interviewed a former Allegiant mechanic, who said "Dedicated steps were not being performed with maintenance manuals or even with general practices, before an aircraft is released.

[69] Public records cited in the investigation found that the airline had more than 100 serious mechanical incidents between January 1, 2016, and October 31, 2017, including "mid-air engine failures, smoke and fumes in the cabin, rapid descents, flight control malfunctions, hydraulic leaks and aborted takeoffs.

"[69] Other public records further revealed that Allegiant aircraft, on average, were nearly three and a half times more likely to have mid-air breakdowns than American, United, Delta, JetBlue and Spirit.

[71][65] As of December 2021, Allegiant offers service to 133[72] destinations throughout the United States, mostly to smaller non-hub regional airports and all usually only a few times each week.

It chooses its routes after calculating expected costs and revenue and adds or ends service to particular destinations as demand warrants.

A total of 35 Airbus A319-100 aircraft in a high-density seating configuration, fitted with four overwing exits, were purchased from easyJet and Cebu Pacific.

[91][92][76] Allegiant plans on retiring the oldest Airbus A320 aircraft in its fleet that are configured with 177 seats, but will continue to operate its other A320s alongside the 737 MAX.