Speaking for the first time as a Chelsea player, Bartel said: "I am very happy to be here at Chelsea. It’s one of the biggest clubs in Europe and I am very excited to be part of this club."
General manager Paul Green added: "Julia is a top young player, who is technically excellent and has good pedigree coming through at Barcelona and the Spanish international youth teams. She has good leadership skills for someone at a young age and we look forward to seeing her develop in the upcoming years."