Platini's bid to succeed Blatter as FIFA president in a 26 Febuary election is now likely to be over.
Ethics judges ruled that Blatter broke FIFA Code of Ethics rules on conflicts of interest, breach of loyalty and offering gifts.
Platini broke rules on conflict of interest and loyalty.
Both denied wrongdoing in 2011 when Platini took $2.8 million of FIFA money approved by Blatter as uncontracted salary for work as a presidential adviser from 1999-2002.
Blatter was fined $70,000 and Platini was fined $112,000.
"Neither in his written statement nor in his personal hearing was Mr. Blatter able to demonstrate another legal basis for this payment," the judges said.
"By failing to place FIFA's interests first and abstain from doing anything which could be contrary to FIFA's interests, Mr. Blatter violated his fiduciary duty to FIFA.