Earlier in the window Bournemouth rejected a permanent bid from Toulouse for the 29-year old with boss Eddie Howe insisting he was an important part of his plans.
However, this week the Cherries accepted the loan deal for Gradel, whose 2 year spell at Bournemouth has been hampered by injury after he damaged a cruciate ligament just four games following his arrival from Saint-Etienne.
Gradel will be able to join up with his new team-mates in time for Toulouse' game against Paris Saint-Germain this weekend.
Having joined Bournemouth for £3m in August 2015 he scored just two goals in 27 appearances in all competitions for the Cherries, starting just 11 games in the league.