The FA had charged Davies with misconduct following allegations that he had used "abusive and/or insulting words and/or behaviour" towards referee Anthony Taylor at half-time of Forest's 2-2 home draw with Championship leaders Leicester City on February 19.
Davies admitted using such language and/or actions, but denied a second charge made under FA Rule E3 that alleged he "deliberately made contact with the match referee".
However, the governing body announced on Tuesday that it had found this charge proven.
A statement on the FA website read: "Following an Independent Regulatory Commission hearing, Nottingham Forest manager Billy Davies will serve a five-match touchline ban with immediate effect, subject to any appeal, in respect of two breaches of FA Rule E3 that took place during his side's game against Leicester City on February 19 2014.
"Davies admitted the first breach that he used abusive and/or insulting words and/or behaviour towards the match referee in or around the tunnel area at half-time of this fixture.
"However, he denied the second breach of improper conduct, which alleged that he deliberately made contact with the match referee. This charge was found proven."
Davies' touchline ban begins with immediate effect.
