The 18 year old had an impressive trial for the Under-21s last season, bagging two goals and two assists in the Premier League International Cup semi-final victory over Everton at Selhurst Park.
Despite joining West Ham at age 10 the forward has now committed himself to another London based team who he cannot wait to get started with.
After putting pen to paper Umolu said:
“It’s an amazing feeling to sign my first professional contract with such a big club, I’m ready to hit the ground running.
“I played a good couple games for the U21s, I played against Stoke and managed to get an assist and obviously I played in the semi-final of the International Cup where I got two assists and a goal. I’m just really excited to get going with the team.”