Moss has penned a contract which keeps him at the club until the summer of 2006.
The 27-year-old, who is a lifelong Cherries fan, came through the youth ranks at Dean Court before signing for neighbours Southampton for £250,000 in December 1995.
However, he struggled to earn a regular place in the Saints team, making just 24 appearances in seven years, under six different managers.
Moss then spent three months on loan at Bournemouth earlier this season to solve a goalkeeping injury crisis.
He is one of six different players - including midfielder Marcus Browning's two stints between the posts - to keep goal for the Cherries this season.
Bournemouth's keepers this season
Moss left Southampton by mutual consent last week and is now relishing the chance of first-team football, although he faces competition from Chris Tardif and Gareth Stewart.
"They've both been unlucky with injuries, but I have a great deal of respect for them and thoroughly enjoy working with them," he told BBC Radio Solent.
"Now it sets up an interesting challenge to see who will grab that first-team shirt.
"I was pleased to help out before, but I can do better than I did on loan, now I'm settled - there's no doubt about that."
His signing marks the end of Bournemouth's transfer embargo, which had been in place since they borrowed money from the Professional Footballers' Association last year.