Forest are happy to loan out Walker as their new boss Aitor Karanka feels he has enough cover in attack for now.
Walker has made 16 appearances in all competitions for Forest this season, but only seven of those have been starts in the Championship.
The speedy forward has scored four goals and created two assists for Forest, but with the club now out of the FA Cup his first-team chances are set to be limited.
Walker was on the bench for Karanka's first game in charge against Aston Villa earlier this month, but he was not named in the squad for the last two matches against Wolverhampton Wanderers in the Championship and Hull City in the FA Cup.
A number of clubs are understood to have made enquiries about Walker's availability before the close of the transfer window, but Bolton have moved quickly to agree a deal with Walker.
Bolton boss Phil Parkinson has been looking to strengthen his attacking options as he looks to steer his side to safety in the Championship, and he sees Walker as a key addition to his plans in the second half of the season.
The son of Forest legend Des Walker has previously been sent out on loan to Burton Albion, Stevenage and Port Vale, for whom he scored a combined six goals in 20 appearances.