The 71-year-old finally fell from grace after decades influencing the media when he was convicted of eight counts of the crime, carried out between 1977 and 1984, on Monday.
Passing sentence at Southwark Crown Court today, Judge Anthony Leonard told him: "These offences may have taken place a long time ago, when inappropriate and trivial sexual behaviour was more likely to be tolerated, but your offending was not trivial, but of a very serious nature."
The judge said that due to the age of the offences that occurred between 1977 and 1984, Clifford was charged under an act from 1956, which set the maximum term at two years.
Under later legislation passed in 2003, the maximum term would have been 10 years, and for the worst instances would have been charged as rape or assault by penetration, which attract a maximum life term, the court heard.
Clifford repeatedly shook his head as the judge made his comments to a packed courtroom.
Judge Leonard added that he thought Clifford's personality and position in the public eye were why the crimes had not been made public sooner.
He said: "The reason why they were not brought to light sooner was because of your own dominant character and your position in the world of entertainment which meant that your victims thought that you were untouchable, something that I think you too believed."
Clifford, who branded his accusers "fantasists", remained defiant ahead of his sentencing, saying: "I stand by everything I have said in the last 17 months."
A string of his clients have moved to distance themselves from the veteran agent in the wake of his conviction, the first under the sex crime inquiry Operation Yewtree.