The 18 year-old, who will complete his move when the transfer window officially opens, has put pen to paper on a five-year deal at the London Stadium.

The Brazil under-20 international will join the Hammers with plenty of experience already under his belt, having won a Brazilian Serie A title with Palmeiras and played in the Copa Libertadores.

Widely regarded as one of the most exciting young talents in South America, he is delighted to fulfil his boyhood dream by making the move to England.

"I'm very happy to be signing with West Ham United, a club that trusted in my work," said Luis Guilherme. "If things go well, we have a beautiful journey ahead.

"The head coach and I have already had a conversation. He showed me his project and I believe I'll learn a lot from him. He's coached at the national level in Spain and managed big clubs.

"The Premier League is the best league in the world. I believe I'll improve a lot here with the entire staff at West Ham, which is crucial for my development.

"Growing up, whenever I had the chance, I watched English football. Seeing how it is and now being able to play here is an incredible feeling. Since I was 11, I have had this dream, and now it's becoming a reality."