UEFA have banned Manchester City from all European competitions for the next two seasons for breaking financial fair play rules.
City were found guilty of not declaring accurate sponsorship revenues in a bid to get around FFP - which aims to prevent football clubs spending more than they earn to attain success.
The governing body cited“serious breaches” of financial and club-licensing rules and also fined City €30m (£25m).
The club say they will appeal the decision.
A statement released by UEFA said: "UEFA takes note of the decision of the independent Adjudicatory Chamber of the Club Financial Control Body (CFCB), issued today, which included the following summary of its content and effect to be announced as required by the Procedural Rules governing the CFCB:
"Following a hearing held on 22 January 2020 the Adjudicatory Chamber of the UEFA Club Financial Control Body (CFCB), chaired by José da Cunha Rodrigues, has today notified Manchester City Football Club of the final decision on the case which was referred by the CFCB Chief Investigator.
"The Adjudicatory Chamber, having considered all the evidence, has found that Manchester City Football Club committed serious breaches of the UEFA Club Licensing and Financial Fair Play Regulations by overstating its sponsorship revenue in its accounts and in the break-even information submitted to UEFA between 2012 and 2016.
— Manchester City (@ManCity) February 14, 2020
"The Adjudicatory Chamber has also found that in breach of the regulations the Club failed to cooperate in the investigation of this case by the CFCB.
"The Adjudicatory Chamber has imposed disciplinary measures on Manchester City Football Club directing that it shall be excluded from participation in UEFA club competitions in the next two seasons (ie. the 2020/21 and 2021/22 seasons) and pay a fine of € 30 million.
'The decision of the Adjudicatory Chamber is subject to appeal to the Court of Arbitration for Sport (CAS). If Manchester City Football Club exercises that right the full reasoned decision of the Adjudicatory Chamber will not be published prior to publication of the final award by the CAS.'
"As noted by the Adjudicatory Chamber, the club has the right to appeal this decision to the Court of Arbitration for Sport. Therefore, UEFA will not be commenting further on this decision at this stage."
Manchester City's response
A statement from Manchester City read: "Manchester City is disappointed but not surprised by today’s announcement by the UEFA Adjudicatory Chamber. The Club has always anticipated the ultimate need to seek out an independent body and process to impartially consider the comprehensive body of irrefutable evidence in support of its position.
"In December 2018, the UEFA Chief Investigator publicly previewed the outcome and sanction he intended to be delivered to Manchester City, before any investigation had even begun. The subsequent flawed and consistently leaked UEFA process he oversaw has meant that there was little doubt in the result that he would deliver. The Club has formally complained to the UEFA Disciplinary body, a complaint which was validated by a CAS ruling.
"Simply put, this is a case initiated by UEFA, prosecuted by UEFA and judged by UEFA. With this prejudicial process now over, the Club will pursue an impartial judgment as quickly as possible and will therefore, in the first instance, commence proceedings with the Court of Arbitration for Sport at the earliest opportunity."
Manchester City sought damages from UEFA over what they alleged were leaks of confidential information to the media concerning their ongoing Financial Fair Play case, court documents show.
Details of City's appeal against UEFA's FFP investigation are contained in written reasons published by the Court of Arbitration for Sport (CAS).