He pleaded guilty in September to two counts of phone hacking as well as making illegal payments to officials and perverting the course of justice.
He was a prosecution witness against his former editor Andy Coulson in the hacking trial.
The judge said he had reduced Evans's sentence as a result.
He said he had taken the guilty pleas and Evans's agreement to give evidence in the hacking trial and possibly other future trials into account.
"In the circumstances of this case, and in particular the co-operation that Mr Evans has given and has agreed to give the police and the prosecution in the future as compared with the lack of co-operation from others, I do feel able to suspend the sentence for a period of 12 months," the judge added.
"I would not have done that had Mr Evans not made a clean breast of his involvement in these offences."
Earlier this month, former News of the World editor Coulson was jailed for 18 months for conspiracy to hack phones.
Five fellow defendants - including former News International chief Rebekah Brooks - were cleared of all charges.
This was despite "undisputed evidence" of a great deal of hacking at the paper from 2004-2006, the judge added.
"Why so few people have been prepared to give evidence in court about what went on is not for me to say but it makes Mr Evans's position unique."
The judge said he would otherwise have given Evans a 24-month sentence and would not have suspended the term.
Meanwhile, four security personnel who worked for Mrs Brooks and her husband Charlie in July 2011 have had charges of perverting the course of justice dropped.
David Johnson, Lee Sandell, Daryl Jorsling and Paul Edwards were formally found not guilty after prosecutors offered no evidence against them.
It was alleged they had been involved in a plot to hide material from police investigating phone hacking.
Mrs Brooks and her husband Charlie were cleared of a similar charge at their trial.
Mrs Brooks was also cleared of conspiracy to hack phones and making illegal payments to public officials.