FIFA has bannned Chelsea from signing players for two transfer windows after being found guilty of breaching rules about signing minors.
The Premier League club have also been fined more than £460,000, while the FA face a £390,000 sanction.
Chelsea can contest the decision in front of the FIFA Appeal Committee.
The club were found guilty of 29 incidences of breaching article 19, which relates to the transfer of players aged under 18.
FIFA have given the club 90 days to rectify the situation concerning the players signed.
The punishments are a result of a three-year FIFA investigation related to the signing of more than a dozen players by Chelsea.
One of the main contentious signings was that of Bertrand Traore in 2013. Chelsea also twice breached regulations relating to third-party influence, article 18bis, FIFA said.
Chelsea will be able to sell players, but not register any new signings.
“This ban applies to the club as a whole – with the exception of the women’s and futsal teams – and does not prevent the release of players,” FIFA said in a statement.
Chelsea were given a transfer ban in 2009 after there was a complaint about the youth player Gael Kakuta joining illegally two years earlier. Chelsea appealed that and had the ban reduced.