Reports suggest the Partenopei have paid Liverpool around €5 million for Dossena.
Napoli confirmed the deal on their website, announcing that Dossena will remain at the Stadio San Paolo until 2014.
"I am happy to be able to wear the Napoli shirt," Dossena said.
"I have chosen a place of great prestige with big plans.
"I can't wait for the time to play at the San Paolo in front of an extraordinary public."
Dossena could make his debut on Sunday at home to Sampdoria.
The 28-year-old has long been linked with a move away from Anfield, having failed to live up to his £7m price tag since moving to Liverpool from Udinese in 2008.
Source: Telegraph
Source: Telegraph