Kim Yu-jin of South Korea defeated world No. 2 Kiani 2-0 (5-1, 9-0) in the final of the women's -57-kilogram at Grand Palais in the French capital.
Earlier in the day, Canada's Skylar Park and Bulgaria's Kimia Alizadeh had won two bronze medals.
Mobina Nematzadeh of Iran had previously claimed a bronze medal in the women's 49kg taekwondo on Wednesday.