The 22-year-old has signed a five-year deal running until the summer of 2031, with Fulham holding an option to extend by a further year. Reports in Spain put the fee at around €40m fixed plus €2m in add-ons, with Real Madrid retaining a 30% sell-on clause and matching rights on any future sale.
Speaking to FFCtv after putting pen to paper, García said: "I'm very grateful, very happy to be here.
"I have to thank the board and Arbeloa for the trust they've put in me, and I'm very, very excited to start."
Fulham owner Tony Khan added: "I'm thrilled to welcome Gonzalo García to Fulham! Gonzalo is a very talented young striker, and he is excited to come to Fulham and play in the Premier League.
"We all believe that Gonzalo will be a tremendous addition to the squad and will prove to be an excellent player for the club under Álvaro's leadership! Come on Fulham!"
García is a Madrid native who joined Real Madrid's academy at the age of 10, spending just a single season away on loan with Mallorca's youth system before returning to La Fábrica in 2019. It was there that his relationship with Arbeloa began, a partnership that bore fruit in 2023-24 when García's 35 goals fired Real's Under-19s to a domestic treble.
He then moved up to Castilla, where a further prolific campaign brought 29 goal involvements in 36 games (25 goals, four assists), a tally made more impressive by the fact that 19 of those contributions came while he was deployed out wide rather than through the middle. That season also produced his first senior goal for Real Madrid, a late winner against Leganés in the Copa del Rey.
His breakthrough truly arrived at last year's Club World Cup: although Real Madrid were eliminated at the semi-final stage, García finished as the tournament's top scorer with four goals, form that prompted then-head coach Xabi Alonso to compare him to club legend Raúl.
That form carried into his first full season in the senior picture, where García scored eight times and set up three more in 39 appearances, the second half of the campaign coming under Arbeloa's own charge at the Bernabéu; the highlight was a perfect hat-trick, header, chest-and-volley and deft flick, in a 5-1 win over Real Betis.
His rise also earned him a first senior call-up for Spain in one of their pre-World Cup warm-up matches, even though he missed the final squad cut, building on six goals in seven caps for the Under-21s, for whom he wore the number seven, the shirt he will now take at Craven Cottage.