Neto has signed a one-year contract with the newly-promoted Premier League side.
The Brazil international spent three years at Barcelona as an understudy to Marc Andre Ter-Stegen and only made 21 appearances in his time at the club.
Neto joined Barcelona from Valencia in the summer of 2019 for £23m.
A statement from the Cherries confirming the transfer read: “AFC Bournemouth have completed the signing of goalkeeper Neto from Barcelona.
“The experienced Brazilian, who turned 33 last month, has joined the Cherries on a free transfer after agreeing terms on a 12-month deal.
“He becomes the club’s fourth summer signing following the arrivals of Joe Rothwell, Ryan Fredericks and Marcus Tavernier.”
Bournemouth chief executive Neill Blake added: "To be able to attract a player of Neto's calibre is very pleasing."
"This is a real coup for the club and we're delighted he has chosen to join us. He has vast experience at the very top level of the game so I'm sure he will be a huge asset for us."
Neto has won one cap for the Brazil national team.
Bournemouth started their Premier League campaign with a 2-0 win over Aston Villa on Saturday.
