The Dutch winger has found himself out of favour at Southampton and has moved on a month-long loan deal while the Sierra Leone international signs from Partizan Belgrade
De Ridder has found first-team chances hard to come by with the Saints, and the Belgian winger has decided to drop a division, where he shone during Southampton's promotion last season, in an attempt to get some game time until February.
The 25-year-old has been with the Saints since 2011 and becomes Bolton's fifth acquistion of the transfer window.
Bolton soon completed their sixth deal as they added Sierra Leone international Mohamed Kamara, also known as Medo, subject to international clearance on a three-and-a-half-year deal from Partizan Belgrade, while an earlier deal on deadline day was completed for 20-year-old Leicester defender Cian Bolger.
Other deals completed for the Trotters in January include the signing of Craig Dawson on loan from West Brom, Craig Davies and Jan Gregus.