"After Australian wing Drew Mitchell, South African Bryan Habana will garnish the ranks of the 'Red and Black' for the next two seasons," Toulon, who will play in the Heineken Cup final on May 18, said in a statement on their website.
Western Province/Stormers wing Habana, 29, won the 2007 World Cup with the Springboks and was voted the International Rugby Board (IRB) player of that year.
Last week, Toulon announced that Australia wing Mitchell would join for the next two seasons from Waratahs.
Mitchell, who has 60 caps with the Wallabies, will join during the European autumn, after the Four Nations.
Both will reinforce the Toulon wings as Rudolffe Nicholas Wulf, Benjamin Lapeyre and David Smith all have limited international experience.
Habana has scored 47 tries from 82 caps with South Africa.
Toulon, who are backed by president Mourad Boudjellal's personal money, have been relying on foreign players to mount their Top 14 and European Cup challenge.
Only four French players featured in the Toulon team who beat Saracens 24-12 in the Heineken Cup semi-finals on Saturday.
Toulon, second in the Top 14, will play the final against pacesetters Clermont Auvergne on May 18 in Dublin.