The 2005 FA Cup Final was held at the Millennium Stadium, Cardiff on 21 May 2005 between Arsenal and Manchester United. In a tense but surprisingly one-sided encounter, Arsenal ran out winners after 120 goalless minutes despite being outplayed throughout the game, becoming the first club to win the cup on penalties. It was the first goalless draw in an FA Cup final since 1912.

The match took place for the fifth consecutive year at the Millennium Stadium, due to the ongoing reconstruction of Wembley Stadium, the final's usual venue. The match was refereed by Rob Styles, who was aided by assistant referees Jim Devine, Paul Canadine and fourth official Neale Barry.

The game was the 17th appearance for both teams in an FA Cup Final, a record that Manchester United surpassed in 2007. It was Arsenal's tenth FA Cup win and their most recent major trophy to date. Only Manchester United have won the trophy more times, with eleven.

The match was the fifth meeting between the two clubs in the 2004–05 season. Despite finishing six points ahead of Manchester United in the league, Arsenal had lost both league fixtures between the clubs, as well as a League Cup quarter-final tie, which was played out by the clubs' fringe and reserve team players. Arsenal had won the season's first encounter, also at the Millennium Stadium, in the FA Community Shield by a 3–1 scoreline.

The FA Cup Final, commonly referred to in England as just the Cup Final, is the last match in the Football Association Challenge Cup. With an official attendance of 89,826 at the 2007 FA Cup Final, it is the fourth best attended domestic club championship event in the world and the second most attended domestic football event. It is the culmination of a knockout competition among clubs belonging to The Football Association in England, although Scottish and Irish teams competed in the early years and Welsh teams regularly compete, with Cardiff City winning the Cup in 1927 and reaching the final in 2008.

Early FA Cup Finals were held at various venues including Fallowfield Stadium but were mainly in London. In the period from 1923 until 2000, the final was held at Wembley Stadium, English football's national stadium. From 2001–2005, the final was moved to Millennium Stadium in Cardiff, during the rebuilding of Wembley Stadium. Millennium Stadium was used again in 2006 due to construction delays in opening the new Wembley Stadium.

Cristiano Ronaldo dos Santos Aveiro,OIH, (born 5 February 1985), commonly known as Cristiano Ronaldo, is a Portuguese footballer who plays as a winger or striker for Spanish La Liga club Real Madrid and is the captain of the Portuguese national team. Ronaldo became the most expensive footballer in history after moving from Manchester United to Real Madrid in a transfer worth £80 million (€93.9 million/$131.6 million). In addition, his contract with Real Madrid, in which he is paid €12 million per year, makes him one of the highest-paid footballers in the world, and his buyout clause is valued at €1 billion as per his contract.

Ronaldo began his career as a youth player for Andorinha, where he played for two years, before moving to C.D. Nacional. In 1997, he made a move to Portuguese giants Sporting Clube de Portugal. Ronaldo's precocious talent caught the attention of Manchester United manager Alex Ferguson, who signed him for £12.24 million (€15 million) in 2003. The following season, Ronaldo won his first club honour, the FA Cup. He also played at Euro 2004 with Portugal and scored his first international goal in the opening game of the tournament against Greece, in addition to helping Portugal reach the final. He was featured in the UEFA Euro All-Star Team of this competition.

Roy Maurice Keane (born 10 August 1971) is an Irish former footballer and manager. In his 18-year playing career, he played for Cobh Ramblers, Nottingham Forest, and Manchester United, before ending his career at Celtic. Keane was a dominating central-midfielder, noted for his aggressive and highly competitive style of play, an attitude which helped him excel as captain of Manchester United from 1997 until his departure in 2005, having joined the club in 1993. Keane helped United achieve a sustained period of success in more than 12 years at the club. He then signed for Celtic but retired as a player less than a year later.

He played at international level for much of his career, representing the Republic of Ireland over a period of 14 years, most of which he spent as captain. He played in every Republic of Ireland game at the 1994 FIFA World Cup, although he was sent home from the 2002 World Cup after an incident with national coach Mick McCarthy.

He was appointed manager of Sunderland shortly after his retirement as a player, and took the club from 23rd position in the Football League Championship in late August to win the division title and gain promotion to the Premier League. Keane's arrival was cited as the catalyst for Sunderland's recovery. He managed to keep Sunderland from relegation in the 2007–08 season, but in his second season as a top-flight manager he left his position with Sunderland in the relegation zone. In April 2009, he was appointed as manager of Ipswich Town, but was sacked by the club in January 2011 with them 19th in the Championship.