Ancelotti added that Real are unlikely to do any more transfer business in the current window which closes on September 1st.
When asked about France striker Mbappe, he told reporters: "No, I rule it out 100%. I think our squad is closed and our players are thinking about our season."
The transfer window remains open in Saudi Arabia beyond September 1st, which means clubs from the Gulf nation could still poach Europe's best players, but the Real boss was not concerned.
"Someone may change their mind, but I am not afraid of that," he added ahead of Real's LaLiga game at Celta Vigo on Friday.
Midfielder Luka Modric did not start Real's first two league games, leading to speculation that the Croatian is unhappy with the situation, something which Ancelotti denied.
"Luka has already defined his future. He has no problem, he will contribute," Ancelotti said.
"It's a special situation for everybody, for him it's strange not to play from the first minute but he will contribute as always."
Ancelotti also said new signing Kepa Arrizabalaga, who joined on loan from Chelsea, will make his debut in goal in Real's first home league game of the season.
Andriy Lunin was the keeper in the opening two wins of the campaign after Thibaut Courtois underwent surgery on a ruptured anterior cruciate ligament (ACL) in his left knee.
