Private detective Glenn Mulcaire will not go to jail despite admitting to his role in the phone hacking at News of the World newspaper.
Mr Mulcaire pleaded guilty to three counts of conspiring to hack phones last year.
The judge described Mr Mulcaire, 43, of Sutton, south London, as "the lucky one", saying it would be wrong to jail him again after he already served a sentence in 2006 when he was first convicted of phone hacking.
The judge sentenced him to six months imprisonment, suspended for 12 months, plus 200 hours unpaid community work.
Labour leader Ed Miliband said the phone hacking case amounted to a verdict on the judgment of the Prime Minister.
"My thoughts today are with the victims of phone hacking, the victims of Andy Coulson's behaviour," he said.
"I think it's right that justice has been done. I think, once again, it throws up very serious questions about David Cameron's judgment in bringing a criminal into the heart of Downing Street despite repeated warnings," Mr Miliband said.
"This is a verdict on Andy Coulson's criminal behaviour but it is also a verdict on David Cameron's judgment," he said.
Phone hacking judge Mr Justice Saunders has attacked the ''unforgivable'' actions of the News of the World in hacking the phone girl of murdered school girl Milly Dowler.
The judge accused the paper, and its then-deputy editor Andy Coulson, of chasing newspaper sales by withholding information about her disappearance from Surrey detectives until their potential scoop hit a dead end.
The former Number 10 spin doctor has been jailed for 18 months after being found guilty of plotting to hack phones while in charge of the paper.
Hacked Off, the group campaigning for a free and accountable press, said the sentencing today of Andy Coulson, Greg Miskiw, Neville Thurlbeck, James Weatherup and Glenn Mulcaire, is "only the beginning."
It has taken far too long for the thousands of innocent victims of this industrial-scale criminal conspiracy to see its perpetrators brought to justice. It is only the beginning of the process. Those victims will insist that no stone is left unturned to get to the full truth of what happened - no matter how high up the scandal went. We now need a proper independent and effective press regulator that actually works for victims and the public in preventing this sort of institutional disregard for the rights of others.
The sentence handed out to the former Downing Street director of communications Andy Coulson over phone hacking shows that "no one is above the law", Prime Minister David Cameron said.
The sentence handed out to former Downing Street director of communications Andy Coulson over phone hacking shows that "no one is above the law", Prime Minister David Cameron has said.
Andy Coulson and three other senior journalists from the News of the World newspaper - Greg Miskiw, Neville Thurlbeck and James Weatherup - were sentenced today for being complicit in industrial scale phone-hacking.
Former reporter Glenn Mulcaire, the former private investigator tasked with hacking, was given a six-month suspended sentence.
News of the World's former chief reporter Neville Thurlbeck and the paper's ex-news editor Greg Miskiw were jailed for six months.
Other former journalist James Weatherup was given a four-month suspended sentence.
Five defendants in the hacking trial, including former News International chief Rebekah Brooks, were cleared of all charges last week.
In his sentencing remarks, Judge Mr Justice Saunders said Andy Coulson clearly thought it was necessary to use phone hacking to maintain the newspaper's "competitive edge".
And he said the delay in the News of the World telling police about the Milly Dowler voicemail in 2002 showed the motivation was to "take credit for finding her" and sell the maximum number of newspapers.
The judge said: "Mr Coulson has to take the major share of the blame of phone hacking at the NotW. He knew about it, he encouraged it when he should have stopped it."
Former Number 10 spin doctor Andy Coulson has been jailed for 18 months after being found guilty of plotting to hack phones while in charge at the News of the World.
Former News of the World editor Andy Coulson has arrived at court - amid a media scrum - for sentencing.
The 46-year-old father-of-three was found guilty last week of conspiring to intercept voicemails at the now-defunct Sunday tabloid following an eight-month trial at the Old Bailey.