The club was founded in August of 2000. Lebanese commercialist Sam Hammam bought the club's assets and was appointed Steve Borley as chairman. Soon after his appointment the chairmanship, he made a controversial pledge to convince the whole Welsh nation to back Cardiff by changing the club's name to "The Cardiff Celts" and changing the colors of the club to red, green and white. After long discussions with the senior players and supporters and players, he concluded that the best strategy was to not alter names of his club. The club's crest was updated and the new design included it with the Cardiff City bluebird in front of the flag of Saint David and featured the club's name superimposed on high-points of the emblem. Hammam provided funding for the signing of numerous new players to Cardiff City, and the new manager Lennie Lawrence led Cardiff to promotion after they took their Second Division play-off in 2003 against Queens Park Rangers. The substitute Andy Campbell came off the bench to score the winning goal of the extra-time period and make sure Cardiff was promoted into Division One after an absence of 18 years.
The club faced growing financial problems in the following years. Plans to build the construction of a new stadium failed get approval from Cardiff Council because of concerns regarding financial security in the year. Hammam was then able to agree to be taken over by an alliance led by the its new chairperson Peter Ridsdale and the lead developer of the venue, Paul Guy. In the 2007-08 season, Cardiff reached the semi-finals of the FA Cup for the first time in 81 years following defeating Middlesbrough with a 2-0 win on the 9th March 2008. After advancing to the semi-final match against Barnsley by a 1-0 victory on the pitch at Wembley Stadium on 6 April thanks to a goal scored by Joe Ledley. However, they lost by 1-0 against Portsmouth at the end of their semi-final.
In May of 2010 Datuk Ghee Chan Tien was appointed chairman of the club in response to a takeover offer by an Malaysian consortium. Vincent Tan also invested and joined the board. Tan then became Cardiff's largest shareholder following the purchase of several other directors . He also acquired approximately 82 percent of the shares of the club. In 2011, the club was appointed by Malky Mackay as their manager. Mackay led the team into the League Cup final for the first time in the club's history in his debut season. The next campaign, Cardiff won the 2012-13 Championship title and was promoted to the top division in English soccer for the very first time in 52 years. On August 18, 2013 Cardiff took on their very first home Premier League match against West Ham United which they lost by 2-0. Cardiff lost just three times during the first part of the season. Then the 27th of December, 2013, Mackay was sacked by Vincent Tan and replaced by Ole Gunnar Solskjaer. Despite the change of management, Cardiff were relegated to the Championship following a single season, following a 3-0 home defeat against Newcastle United. Solskjaer was dismissed on September 18, 2014, following an unsatisfactory start to the Championship season. He was then replaced with Leyton Orient manager Russell Slade.
In October of 2016, Neil Warnock was appointed the first-team manager at Cardiff. Warnock became the manager in the midst of Cardiff at the bottom of the table following two wins in 11 games. He led the team to a 12th-place final after a strong performance. The 2018 season witnessed Cardiff set a new record of their club when they won their first three league matches of the season for the first occasion in the club's nearly 107-year professional history. The club was promoted into the Premier League after finishing second in the league table. However, they were sent again to the Championship following a single season.
Warnock quit as manager in November of 2019 after a disappointing start to the season . He then was succeeded by Neil Harris. Harris led Cardiff to 5th place but was beaten in the Championship semi-final of the playoffs. After six consecutive defeats Harris was dismissed on January 21 in 2021. The new replacement Mick McCarthy, was appointed the next day. McCarthy began his career with a bang with 7 wins and scoring 3 of his first 10 games. He also helped Cardiff to an eighth place final, and a brand new contract for two years during the process. City also got off to a great start in 2021/22, but the form faltered after they lost 8 games in a row, before McCarthy was let go of his duties as the team was just two points ahead of being relegated. The manager for the under 23s Steve Morison was appointed as manager in caretaker capacity before signing an 18-month contract following his successful guide of the Bluebirds to the safety of.