Three of the five FIFA candidates claim support from Asian voters, but the AFC said its 24-member executive committee fully backed Sheikh Salman, a member of the Bahraini royal family.
Asia has 46 of 209 voting federations in the election to succeed Sepp Blatter on February 26.
"The members of the AFC executive committee passed a resolution urging all member associations to unite behind and support the AFC president Sheikh Salman in his efforts to be elected as the first FIFA president from Asia," the continental soccer body said.
However, the AFC chief currently also faces competition from rival candidate Prince Ali bin al-Hussein of Jordan, who is supported by his home country and other Asian voters.
Jerome Champagne of France claims support from the Palestinian federation, which he has advised in recent years and has a delegate on the AFC executive committee.