But he was told by Chelsea that though he was now probably "unemployable" in football, his job would be kept open for him once he is released.
Rix, 41, who has four children, looked shaken as he was sentenced by Judge Timothy Pontius at Knightsbridge Crown Court, London.
The former player, who was capped for England 17 times and is regarded as one of the country's top coaches, had pleaded guilty at an earlier hearing to one count of unlawful sex and one of indecent assault.
The court had heard that Rix and the girl had sex at a London hotel on 27 February last year, on the eve of Chelsea's Premiership match with Manchester United.
Rix, of Richmond, southwest London, was also told by the judge that he would have to remain on the sex offenders' register for the next 10 years. He will be released after serving half of the sentence, after which he will remain subject to the terms of licence.
The judge said that the girl had regarded Rix as a kind man and had trusted him and "therefore was willing to go at your invitation to your house and your hotel bedroom". He accepted the girl made no strong protests to Rix's advances.
The judge pointed out that Rix had a pornographic movie on the television in his hotel room and that he had refused to use a condom despite the girl's specific requests and his knowledge that she was a virgin at the time.
After the hearing Colin Hutchinson, Chelsea's chief executive, said: "He is probably unemployable in football, but the job will be kept open and he will return to his post."Reuse content