The Poznań Celebration or Grecque is a form of sporting celebration, which is associated with the supporters of Polish football club Lech Poznań and other European teams. The first use of this celebration is thought to have been in protest to how the football club was being run, the fans wanted to still support their team but show their disapproval whilst at matches therefore would turn their back on the team. The celebration involves supporters standing with their backs to the pitch, linking shoulders side-by-side and jumping on the spot in unison. It is mostly associated with Lech Poznań in Poland, the Republic of Ireland national football team, Manchester City supporters in England, the Western Sydney Wanderers in Australia and Celtic in Scotland (where it is known as 'The Huddle').
The Poznań Celebration involves the fans turning their backs to the pitch, joining arms and jumping up and down in unison. It originated in 1961. In Poland, and among many fans across Europe, it is not called "the Poznan" but is known as a "Grecque", and it is performed by fans of many teams.
Despite initially failing to impress Manchester City fans when it was done during the teams' meeting in the UEFA Europa League on 21 October 2010, it was subsequently adopted by City supporters during a game early the following month. The activity was coined 'The Poznan' by Manchester City fans, in homage to the club that inspired them to celebrate in this way. Apart from odd occasions, it died out as a regular celebration within a couple of seasons.
The Poznań was briefly adopted by other English football supporters, notably those of Leicester City after their clash with Manchester City in the third round of the FA Cup in January 2011, and is referred to by English football fans, and by the British media, as "doing the Poznań".
It has also been used to mock Manchester City fans, such as when newly promoted Cardiff City beat them 3-2 in August 2013. More examples include when Arsenal supporters did the Poznań celebration after Mikel Arteta scored the winning goal for Arsenal in April 2012 and when Arsenal beat Manchester City in the Premier League. Manchester City's local rivals Manchester United supporters did it during a Manchester derby game during the 2011–12 FA Cup  as well as Bayern Munich fans during a Champions League group match against them in October 2013. Arsenal supporters also did the Poznan in January 2015, when Arsenal beat Manchester City by 0-2.
Initially the supporters group of Australian club Western Sydney Wanderers, The Red and Black Bloc, performed it in the 80th minute of matches to represent the first football match played in Western Sydney in 1880. Subsequently this has grown into an all stadium celebration. In return their local rival, Sydney FC and their hard-core supporters "The Cove" have performed it in retribution when they are in a winning position as the 90th minute nears during their local derby.
Fans of the Scottish club Celtic have a similar celebration known as "The Huddle", whilst also facing away from the pitch; the words sung by the fans are "Let's All Do The Huddle". The "Huddle" performed by Celtic fans is closely linked to the on-field huddle conducted by the Celtic team prior to kick-off which was introduced by Tony Mowbray during his playing career at the club in the mid 1990s. Over the years Celtic fans have carried out various versions of the huddle, although the first example of it being performed by large numbers of the club's supporters at a game was during a 3-0 win over Rangers at Celtic Park in February 2011.
- The Bouncy
- Mexican wave
- "Jump Around", a 1992 song by American hip hop group House of Pain used as the backdrop for similar fan actions
- "Video: Poznan, Selebrasi Sindiran Gooners Untuk Manchester Biru". Bola.net. 2011-04-09. Retrieved 2011-04-29.
- "Manchester City fans all do the Poznan at Wembley during victory over United". London: Daily Mail. 2011-04-16. Retrieved 2012-04-20.
- "The "Poznań" and the Death of the Goal Celebration?". Modern-football.co.uk. 2011-05-20. Retrieved 2012-04-20.
- Pitt-Brooke, Jack (2011-04-20). "Poles apart: how fans of Poznan inspired City's unlikely dance craze". The Independent (London). Retrieved 2012-04-29.
- Sloan, Jenna (2011-02-21). "Man City fans are doing the Poznan". London: The Sun. Retrieved 2012-04-20.
- "Manchester City 4 Leicester 2: Roberto Mancini's revolution is on target for FA Cup glory". London: Daily Mail. 2011-01-19. Retrieved 2012-04-20.
- Jacob Steinberg (2012-04-08). "Arsenal v Manchester City - as it happened". London: Guardian. Retrieved 2012-04-20.
- Nick Metcalfe (2012-01-09). "Manchester United fans do the Poznan against Manchester City". London: Daily Mail. Retrieved 2012-04-20.
- "1906 Ultras Poznan in Palo Alto 2012".
- Murray, Ewan (16 June 2009). "Tony Mowbray confirmed as new manager of Celtic". The Guardian. Retrieved 3 October 2013.
- "Celtic fans Huddle". Youtube. Retrieved 3 October 2013.
- "Celtic 3 - 0 Rangers (20 February 2011)". Youtube. Retrieved 18 November 2014.