UEFA have banned Galatasaray from participating in European competitions for one season should they qualify in either of the next two seasons after breaching Financial Fair Play regulations.
The Turkish champions were referred to the CFCB adjudicatory chamber last month, with UEFA revealing that "the club has failed to comply with the break-even requirement during the monitoring period assessed in the 2015-16 season".
Three other clubs who were investigated - Hull City, Panathinaikos and Sporting CP - were found to have fully complied with settlements, but Gala were ruled not to have done so.
Uefa's statement read: "The Adjudicatory Chamber of the UEFA Club Financial Control Body (CFCB) today announced that Galatasaray AS will be excluded from participating in the next UEFA club competition for which they would otherwise qualify in the next two (2) seasons (i.e. the 2016-17 and 2017-18 seasons).
"This decision was taken after Galatasaray failed to comply with the terms of the settlement agreement that it entered with the CFCB Chief Investigator in May 2014 under Article 15 of the Procedural rules governing the UEFA CFCB.
"The Turkish club has also been ordered to limit the overall aggregate cost of the employee benefits expenses of all its players in each of the next two reporting periods (i.e. the reporting period ending in 2016 and the reporting period ending in 2017)."
Galatasaray finished third in Champions League Group C this season and were knocked out of the Europa League last 32 by Lazio.
They are fifth in this season's Turkish Super Lig after 23 matches and head coach Mustafa Denizli resigned on Tuesday less than four months after taking over at the Turk Telekom Arena.