Neil Wallis broke down in tears as a London jury announced the verdict today.
His former editor, Andy Coulson, was sentenced to 18 months in prison last year for conspiring to hack phones.
Prosecutors argued it was inconceivable Wallis did not know about the practice. Wallis denied involvement.
Wallis is the last employee of the tabloid to face trial over illegal eavesdropping on the phones of celebrities and people in the public eye. Eight have been convicted.