The Scot vented his anger at referee Kevin Friend after Villa's 3-1 defeat to Chelsea last month and the FA have ruled that his comments brought the game into disrepute.
Lambert's ire centered around an incident between Branislav Ivanovic and Christian Benteke, when the Villa boss felt the Serb had caught his striker with an elbow.
The 44-year-old questioned how Friend had missed the incident, saying: "He [Ivanovic] clearly elbowed Christian".
The governing body confirmed the decision in a statement on Friday.
"Following an Independent Regulatory Commission hearing, Aston Villa manager Paul Lambert has been fined £8,000 in relation to post-match media comments he made after his side’s game against Chelsea on 21 August 2013," the statement read.
"The misconduct charge, which Lambert admitted, was that the comments implied the match referee was motivated by bias; and/or brought the game into disrepute, in contravention of FA Rule E3(1)."