The bans have been imposed by FIFA's ethics judge Hans-Joachim Eckert for a "disloyal payment" of 2million Swiss francs (£1.3million) made to Platini in 2011, signed off by Blatter.
Blatter has also been fined 50,000 Swiss francs (£33,700) and Platini 80,000 Swiss francs (£54,000) by the adjudicatory chamber of FIFA's ethics committee after being found guilty of ethics code breaches.
The charges found proven included offering and accepting gifts, conflict of interest, and violating their fiduciary duty to FIFA.
A statement from the ethics committee says: "Mr Blatter's actions did not show commitment to an ethical attitude, failing to respect all applicable laws and regulations as well as FIFA's regulatory framework to the extent applicable to him and demonstrating an abusive execution of his position as president of FIFA, hence violating article 13 of the FCE (general rules of conduct)."
It adds: "Mr Platini failed to act with complete credibility and integrity, showing unawareness of the importance of his duties and concomitant obligations and responsibilities.
"His actions did not show commitment to an ethical attitude, failing to respect all applicable laws and regulations as well as FIFA's regulatory framework to the extent applicable to him and demonstrating an abusive execution of his position as vice-president of FIFA and member of the FIFA executive committee."
Outgoing FIFA president Blatter and UEFA president Platini claim the payment was made following a verbal agreement between the pair when the Frenchman worked for Blatter from 1998 to 2002.
The explanation was rejected as "not convincing" by the ethics committee, which added the evidence had not been sufficient to secure charges of corruption.
Blatter's personal advisor Klaus Stoehlker confirmed to Press Association Sport that he will appeal against the ban and take the case to the Court of Arbitration for Sport in Lausanne. Platini is likely to follow suit - he had aimed to succeed Blatter as FIFA president in February's election but those hopes have been effectively ended, even if he manages to overturn the ban.
There is also the threat of action from the law authorities in the USA and Switzerland. The Swiss attorney general announced in October he had opened criminal proceedings against Blatter in connection to the 2million Swiss franc payment. The attorney general also stated he had interviewed Platini as someone "between a witness and an accused person".
Blatter, 79, arrived at FIFA's former headquarters in Zurich ahead of a news conference - he has hired it as a private citizen, but it still houses FIFA's marketing department. Blatter has already claimed in media interviews that the ethics committee has no power to remove him as president.
Full Fifa Ethics Committee statement:
"The adjudicatory chamber of the ethics committee chaired by Mr Hans Joachim Eckert has banned Mr Joseph S. Blatter, president of FIFA, for eight years and Mr Michel Platini, vice-president and member of the executive committee of FIFA and president of UEFA, for eight years from all football-related activities (administrative, sports or any other) on a national and international level. The bans come into force immediately.
The proceedings against Mr Blatter primarily related to a payment of CHF 2,000,000 transferred in February 2011 from FIFA to Mr Platini. Mr Blatter, in his position as president of FIFA, authorised the payment to Mr Platini which had no legal basis in the written agreement signed between both officials on 25 August 1999. Neither in his written statement nor in his personal hearing was Mr Blatter able to demonstrate another legal basis for this payment. His assertion of an oral agreement was determined as not convincing and was rejected by the chamber.
The evidence available to the adjudicatory chamber in the present case was not sufficient to establish, to the extent required, that Mr Blatter sought the execution or omission of an official act from Mr Platini within the meaning of article 21 paragraph 1 of the FIFA code of ethics (FCE) (bribery and corruption).
However, the conduct of Mr Blatter towards Mr Platini without a legal basis constituted a breach of article 20 paragraph 1 of the FCE (offering and accepting gifts and other benefits).
Furthermore, Mr Blatter found himself in a situation of conflict of interest, despite which he continued to perform his related duties, failing to disclose said situation and the existence of personal interests linked to his prospective activities, thus violating article 19 paragraphs 1, 2 and 3 of the FCE (conflicts of interest).
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 and breached article 15 of the FCE (loyalty).
Mr Blatter's actions did not show commitment to an ethical attitude, failing to respect all applicable laws and regulations as well as FIFA's regulatory framework to the extent applicable to him and demonstrating an abusive execution of his position as president of FIFA, hence violating article 13 of the FCE (general rules of conduct).
In consequence, Mr Blatter has been banned for eight years from all football related activities and fined CHF 50,000.
The investigation into the case of Mr Blatter was conducted by Mr Robert Torres, member of the investigatory chamber of the ethics committee. The investigation resulted in a final report which was submitted to the adjudicatory chamber on 20 November 2015. The adjudicatory chamber opened formal proceedings on 23 November 2015, and the hearing of Mr Blatter took place in Zurich on 17 December 2015.
The proceedings against Mr Platini primarily related to a payment of CHF 2,000,000 that he received in February 2011 from FIFA. The payment to Mr Platini had no legal basis in the written agreement signed between both officials on 25 August 1999. Mr Platini's assertion of an oral agreement was determined as not convincing and was rejected by the chamber.
The evidence available to the adjudicatory chamber in the present case was not sufficient to establish, to the extent required, that Mr Platini obtained the payment for the execution or omission of an official act within the meaning of article 21 paragraph 1 of the FCE (bribery and corruption).
Nevertheless, the conduct of Mr Platini without a legal basis constituted a breach of article 20 paragraph 1 of the FCE (offering and accepting gifts and other benefits).
Furthermore, Mr Platini found himself in a situation of conflict of interest, despite which he continued to perform his related duties, failing to disclose said situation and the existence of personal interests linked to his prospective activities in violation of article 19 paragraphs 1, 2 and 3 of the FCE (conflicts of interest).
By failing to place FIFA's interests first and abstain from doing anything which could be contrary to FIFA's interests, Mr Platini also violated his fiduciary duty to FIFA and breached article 15 of the FCE (loyalty).
In addition, Mr Platini failed to act with complete credibility and integrity, showing unawareness of the importance of his duties and concomitant obligations and responsibilities.
His actions did not show commitment to an ethical attitude, failing to respect all applicable laws and regulations as well as FIFA's regulatory framework to the extent applicable to him and demonstrating an abusive execution of his position as vice-president of FIFA and member of the FIFA executive committee, hence violating article 13 of the FCE (general rules of conduct).
In consequence, Mr Platini has been banned for eight years from all football related activities and fined CHF 80,000.
The investigation into the case of Mr Platini was conducted by Ms Vanessa Allard, member of the investigatory chamber of the ethics committee.
The investigation resulted in a final report which was submitted to the adjudicatory chamber on 20 November 2015. The adjudicatory chamber opened formal proceedings on 23 November 2015, and the hearing took place in Zurich on 18 December 2015 in the presence of Mr Platini's lawyers."