The 17-year-old has been handed a new two-year deal after impressing for the under18s at Upton Park.
“I found out a couple of weeks ago when Alex Dyer had a word with me after training,” Moncur told the club’s official website.
“I told my Dad and he was really happy and told me to work hard and keep doing well.
“It helps so much to have a dad who has been through the same experiences himself. He tells me lots and I’ve just got to take it all on board and listen to what he says.”
