Robinson, 21, played for the Trotters development squad while on loan from the Premier League outfit last season.
The Saints academy graduate played just once for the first team, as a substitute in a League Cup win against Sheffield Wednesday in September 2012.
He becomes the fourth addition to the Bolton squad, joining Neil Danns, Liam Trotter and Liam Feeney at the club.
Bolton will sign midfielder Andy Robinson on a one-year deal when his Southampton deal expires this summer.