Airdrieonians Football Club, commonly known as Airdrie, is a Scottish professional football team in Airdrie, North Lanarkshire, who compete in the Scottish Championship as members of the Scottish Professional Football League. They were formed in 2002 as Airdrie United Football Club following the folding of the original Airdrieonians, before returning to its traditional name on 1 June 2013.

The club have won three trophies in their short history – the Scottish Second Division in 2003–04 and the Challenge Cup in 2008–09 and 2023–24. Once described as "the luckiest team in the Scottish League", the club have benefited in league division placements due to other club's misfortunes on four occasions (2008, 2009, 2012 and 2025). However the club have lost six Scottish league play-off finals (2007, 2008, 2009, 2012, 2021 and 2022), two semi-finals (2010 and 2017) and one quarter-final (2024) in total, eventually offset by two Championship play-off final victories, in 2023 against Hamilton Academical and 2025 against Cove Rangers.

The club was formed in 2002 as Airdrie United, following the bankruptcy of the original Airdrieonians.

Airdrieonians had finished runners-up in the Scottish First Division in the 2001–02 season but went out of business with debts approaching £3 million. The collapse of "The Diamonds", as they were known due to their distinctive kits, created a vacancy in the Scottish Football League (in the Scottish Third Division). Accountant and Airdrieonians fan Jim Ballantyne attempted, with the help of others, to gain entry with a club called "Airdrie United" who were essentially to be a reincarnation of Airdrieonians. Their application however was rejected as the then English Northern Premier League side Gretna were preferred by league members over the new Airdrie United.

Airdrie United then went on to complete a buy-out of the ailing Second Division side Clydebank and with SFL approval the club was relocated to Airdrie, the strips were transformed to resemble that of Airdrieonians, and the name was changed to Airdrie United. While this means that the club is therefore officially a legal continuation of Clydebank, it is almost universally accepted as a reincarnation of Airdrieonians, with a new version of Clydebank being reformed by supporters' groups and entering into the West Region Junior League.

Managed by Sandy Stewart, Airdrie United's first match took place at New Broomfield against Forfar Athletic in August 2002, with captain Stephen Docherty scoring the only goal of the game with Airdrie United winning 1–0. Their debut season saw the club only narrowly fail to achieve promotion by one point due to a late injury-time goal from Brechin City which saw them promoted instead. The club reached the second round of the Challenge Cup, the third round of the Scottish Cup and the third round of the Scottish League Cup having beaten Premier League side Kilmarnock in the second round.

During the rest of Stewart's tenure the club reached the final of the Challenge Cup in 2003 (losing 2–0 to Inverness Caledonian Thistle), and won the Second Division title in 2003–04 season. Having started poorly Airdrie went on a run that saw them unbeaten in the last 18 games of that season, including the final game of the league campaign which saw a crowd of over 5,700 at New Broomfield to watch Airdrie defeat Morton 2–0 and lift the League Championship trophy, the club having been confirmed champions the previous week following their 1–0 victory away to Alloa Athletic at Recreation Park.

In November 2006, Stewart was sacked and replaced by former Airdrieonians player and Airdrie United coach Kenny Black, his first management post.