SkyTeam is one of the world's three major airline alliances. Founded in June 2000, SkyTeam was the last of the three alliances to be formed, after Star Alliance and Oneworld. Its annual passenger count is 624 million customers (2024), the second largest of the three major alliances."SkyTeam FACTSHEET 2019." . SkyTeam FACTSHEET 2019. Retrieved 10 May 2019. , SkyTeam consists of 18 active carriers; it also operates a cargo alliance named SkyTeam Cargo, which partners with seven carriers, all SkyTeam members. Its centralised management team, SkyTeam Central, is based in Amstelveen, Netherlands.

History Formation and early years On 22 June 2000, representatives of Delta Air Lines, Aeroméxico, Air France, and Korean Air held a meeting in New York to form a third airline alliance. These became the four founding carriers of SkyTeam. Upon its formation, SkyTeam would offer its customers 6,402 daily flights to 451 destinations in 98 countries. In , the alliance established a cargo alliance, SkyTeam Cargo. The group's inaugural members were Aeromexpress, Air France Cargo, Delta Air Logistics and Korean Air Cargo. The following month, the newly established airline alliance announced its intentions to incorporate CSA Czech Airlines as the 5th member in April of the following year.

The alliance saw the joining of CSA Czech Airlines on 25 March 2001; Alitalia entered SkyTeam on 27 July the same year, with its membership scheduled to become effective 1 November that year. On 30 September 2001, the alliance received KLM's application for membership, following the airline's plans to create a leading airline group with Air France. In 2003, Delta's subsidiary, Delta Express, was replaced by Song. That same year, SkyTeam also launched an improved website focused on providing passengers with more information, increased interactivity and other resources.

2000s: First major expansion, departure of airlines and new initiatives On 24 May 2004, Aeroflot signed a memorandum of understanding with SkyTeam as it intended to become a full member. The event took place in the Kremlin following the airline's application earlier in the year for membership. SkyTeam expressed that Aeroflot has not met the consortium's standards, but that the airline's large hub networks made it ideal for the alliance, and made up for its deficiencies.

On 28 August, China Southern Airlines, the largest carrier of the People's Republic of China, signed a preliminary agreement in Guangzhou in its bid to become a full member. In the presence of some Chinese and airline officials, Yan Zhiqing, the chairman of China Southern Airlines, said, "This agreement-signing event is an important step forward into the future for China Southern Airlines to adapt itself to the need of further reforms and opening to the international community, as it will strengthen the airline's international cooperation and global competitiveness."

On 13 September, Continental Airlines, KLM, and Northwest Airlines joined the alliance. Their simultaneous entry was the largest expansion event in airline alliance history. As a result of the three new members, SkyTeam surpassed Oneworld to become the second largest airline alliance, serving more than 341 million customers with 14,320 daily flights to 658 destinations in 130 countries.

Even though member CSA Czech Airlines pledged to help Malév Hungarian Airlines become an associate member of the alliance (as opposed to a full member, an associate has no voting rights), Malév Hungarian Airlines opted to join the Oneworld airline alliance, signing a memorandum of understanding late in May. A few days later, SkyTeam announced four new associate members due to join by 2006, each one being "sponsored" by an existing member: Madrid-based Air Europa (sponsored by Air France), Panama-based Copa Airlines (sponsored and partly owned by Continental Airlines), Kenya Airways (sponsored and partly owned by KLM), and Romania's TAROM (sponsored by Alitalia). Every associate adopted a frequent-flyer program of a full member: Copa Airlines already used Continental OnePass; Kenya Airways and Air Europa used Air France–KLM Flying Blue.

Following a 23-month joining process since , Aeroflot joined on 14 April 2006. It was the first Russian airline to be associated with any airline alliance. Aeroflot had increased its operational standards, passing International Air Transport Association's (IATA) Operational Safety Audit (IOSA). Delta's subsidiary Song continued to operate as Delta Air Lines. In June, it was announced that Portugália would become the alliance's next associate member candidate. However, in November, rival airline and Star Alliance member TAP Air Portugal purchased 99.81% of the airline, bringing a sudden end to its candidacy.SkyTeam Focused on Alliance Development as Portugalia Airlines Becomes Associate Airline Candidate; China Southern Makes Progress Toward Membership Governing Board provides recruitment, network and services updates from http://www.skyteam.com 2 June 2006

On 4 September 2007, Air Europa, Copa Airlines, and Kenya Airways became members of SkyTeam's Associate program, which was launched to serve airlines in strategic regions which intended to become affiliated with the alliance. China Southern Airlines joined SkyTeam on 15 November to become the 11th full member and the first carrier from China to join the alliance.

In , following an agreement between Continental Airlines and United Airlines, the former, as well as Copa Airlines, announced their intentions to move to Star Alliance after Continental's final flight with SkyTeam on 24 October 2009. That day, as announced, Continental Airlines and Copa Airlines simultaneously left SkyTeam. Continental Airlines joined Star Alliance three days later; at the time, it was rumored that the switch was Continental's initial move in a United-Continental merger.In , the alliance signed a preliminary agreement with Vietnam Airlines for the airline to become a full member in . Also in 2009, Alitalia-Linee Aeree Italiane re-launched operations as the new Alitalia, and the alliance announced initiatives towards a centralized management based in Amsterdam. The consortium also named a new managing director, Marie-Joseph Malé, outlined a timeline for the opening of its co-located facilities at London Heathrow Airport, and unveiled a new special livery.

In , Olympic Air entered into a codeshare agreement with Delta, a deal that was part of Olympic's intention to join SkyTeam and engage in further discussions with Delta's joint venture partner Air France–KLM.Case No COMP/M.5830 – Olympic/ Aegean Airlines , REGULATION (EC) No 139/2004 MERGER PROCEDURE, Article 8 (3), Date: 26/01/2011Air France and KLM Ink Deal with Greek Carrier for Island Connections However, ties were cut in 2010 when Olympic announced intention to merge with Aegean Airlines, with the merged carrier being a member of Star Alliance, which Aegean was in the process of joining.

2010s: Second major expansion and tenth anniversary To start 2010, Northwest Airlines' and Delta Air Lines' operating certificates were officially combined on 1 January, while on 9 March, China Southern Airlines announced its plans to join SkyTeam Cargo. With membership expected to be granted in November the same year, the airline was to be the first Chinese carrier to join a global air cargo alliance. On 16 April, China Eastern Airlines announced its intention to join SkyTeam, with the official joining ceremony initially expected to occur by mid 2011. The announcement came shortly after the airline's merger with Shanghai Airlines, a member of SkyTeam's rival Star Alliance.

On 10 June, Vietnam Airlines became a full member following a joining ceremony held in Hanoi. The airline became the first SkyTeam carrier from Southeast Asia, where Star Alliance has a strong presence through Singapore Airlines and Thai Airways International. With an extra 20 unique destinations added to SkyTeam's route map, Vietnam Airlines helped to strengthen the alliance's foothold in the region.

On 22 June, the CEOs and chairmen of the 13 member airlines gathered in New York to celebrate the alliance's 10th anniversary. During its first decade of operation, the world's second-largest airline alliance more than tripled its membership, doubled its flights and nearly doubled its destinations. On the same day, SkyTeam announced that it had renewed its membership program, thereby upgrading Air Europa, Kenya Airways, and TAROM statuses from associate to full members. During the ceremony, the Board outlined its plans to recruit members from Latin America, South America, and India. Three days later, TAROM officially became the 13th SkyTeam member. As a part of the celebration, SkyTeam offered reductions of round-the-world fares and other promotions. Following the 10th anniversary, SkyTeam intended to enhance customers' travel experience and deepen cooperation among its members to supplement the expansion into regions that are yet to have SkyTeam members.

During the year, Delta Air Lines offered  billion to Japan Airlines after the Asian airline filed for bankruptcy due to  billion debt, at the same time lobbying Oneworld's largest member in Asia to switch to SkyTeam. Delta, along with American Airlines, wanted Japan Airlines to be in their respective alliances to benefit from the U.S.–Japan Open Skies agreement. Eventually, Japan Airlines opted to remain at Oneworld, citing that the transfer to SkyTeam would confuse its passengers and may not gain antitrust immunity from U.S. regulators.

SkyTeam received its second application for full membership within five months. China Airlines, Taiwan's flag carrier and largest airline, announced in mid that it had formally started the joining process. Upon joining, the airline's route network supplemented those of China Southern Airlines and China Eastern Airlines, allowing cooperation among the three airlines. The following month, Aerolíneas Argentinas signed an agreement to officially start the process of becoming the first South American SkyTeam member. The airline was set to join in 2012.

On 1 November, Shanghai Airlines exited from Star Alliance to join SkyTeam in the future under its parent company, future SkyTeam member China Eastern Airlines. This bolstered SkyTeam's presence in the People's Republic of China and surrounding areas, making SkyTeam the number one alliance in the region. Garuda Indonesia formally started its joining process on 23 November and was scheduled to be integrated by 2012.

On 10 January 2011, Saudi Arabian Airlines signed an agreement to join SkyTeam in 2012. On 28 February the same year, Middle East Airlines agreed to join the alliance. Member airlines Delta and Air France–KLM appointed Goldman Sachs in late to advise them on a potential bid for Sir Richard Branson's 51% stake in Virgin Atlantic, which could lead to the airline joining SkyTeam and would sharply increase the alliance's footprint in London. Rivals Star Alliance and Etihad Airways were also investigating competing options about Virgin Atlantic. China Eastern Airlines joined the alliance on 21 June 2011, along with its subsidiary, Shanghai Airlines, to become the 14th member. Later in 2011, on 28 September, China Airlines joined the alliance. In the same year, XiamenAir committed to be incorporated as a full member by the end of 2012, with their entry supported by China Southern Airlines.