Trade show giant Eurovet, which organises both shows said the move was a "strategic decision" which had been "called for by the majority".
The forthcoming edition of Mode City will be held on September 6-8 at Porte de Versailles in Paris. It is unclear when the autumn edition of Interfilière will be held.
The shift to Paris will put Mode City on the same dateline and location as womenswear shows Premier Classe and Prêt à Porter.
Eurovet said in a statement: "The relocation of a renewed version of Mode City and Interfilière within the wave of fashion trade fairs in Paris in September, will offer exhibitors and visitors immediate new benefits, enabling them to take advantage of market synergies between ready-to-wear and beachwear and giving them a comprehensive overview of the fashion offering for summer 2009."