It's been more than 120 years since the Wright brothers ushered in the pioneer era of aviation and 110 years since the world's first scheduled commercial passenger flight.

Airlines began popping up all over the world in the early 20th century but only a handful of those original carriers are still in operation today.

Here's a look at the 10 oldest airlines still in operation as of 2024.

Founded less than one year after the conclusion of World War I, KLM Royal Dutch Airlines was established on October 7, 1919, and completed its first flight in May 1920. The Dutch flag carrier is currently the oldest operating airline in the world.

Colombia's largest airline, the new-look avianca was founded as SCADTA just two months after KLM in December 1919. SCADTA merged with the state-owned SACO during World War II to form avianca, which today is the oldest operating airline in the Western Hemisphere.

Founded in November 1920, Qantas commenced operations two years later and has been operating for more than a century. It's the oldest operating airline in the English-speaking world. With a fleet of 125 aircraft, Australia's flag carrier flies to more than 100 destinations around the world.

Originally founded as Dobrolyot in February 1923, Aeroflot took on the name we recognize today one decade later. It was one of the largest airlines in the world during the Soviet Union era and is currently the largest airline operating in Russia.

Czech Airlines was founded as Czechoslovak State Airlines in October 1923 and adopted its current name in the early 1990s following the breakup of the Czechoslovak Federation. Headquartered in Prague, the Czech Republic's flag carrier was the world's first to fly regular jet-only routes, operating between Prague and Moscow.

Finnair was founded in November 1923 and operated its first flight the following spring. Finland's flag carrier began as Aero O/Y and adopted its current name in the late 1960s. Today, the carrier is celebrated as one of the world's safest carriers.

Tajikistan-based Tajik Air is coming up on its 100th anniversary, which it will celebrate on September 3, 2024. The carrier was originally founded as a division of Aeroflot a century ago but became independent in the early 1990s. Tajik Air suspended operations amid the pandemic but continues to eye an eventual return to service.

Set to celebrate its 100th anniversary next year, Delta Air Lines is the oldest operating U.S. airline. The Atlanta-based carrier was founded in Macon, Georgia as Huff Daland Dusters for crop dusting in March 1925 before being renamed Delta Air Service three years later. Delta is currently the largest airline in the world by several metrics, including revenue, assets value, fleet size and market capitalization.

Delta's rival American Airlines was founded only 13 months later in April 1926 but wouldn't commence operations for another decade. American's parent company American Airlines Group is the world's largest in terms of passengers carried. American is headquartered in Fort Worth, Texas but has hubs all over the U.S.

Although Air Serbia has only been operating under its current name for just over a decade, the Belgrade-based carrier has been around for nearly a century. Founded in June 1927 as Aeroput, it later became known as JAT following World War II and eventually Jat Airways when the country was renamed Serbia and Montenegro in 2003. Air Serbia was born when the carrier entered into a strategic partnership with Etihad Airways in the summer of 2013.