Yarmolenko from Borussia Dortmund on a four-year contract.
“I am very happy to sign for West Ham United,” said Andriy Yarmolenko. “West Ham is a big club with good fans and I am happy to come to play in the Premier League.
“The Premier League is the best league in the world and I know that an interesting project is being built here at West Ham. The team wants to achieve high things and I am excited for this challenge.”
Yarmolenko’s arrival takes West Ham’s spending above the £50m mark, with Ryan Fredericks, Issa Diop, Lukasz Fabianksi and Jack Wilshere having all moved to the London Stadium this summer.
West Ham’s director of football, Mario Husillos, said the club “did not hesitate” when the opportunity to sign Yarmolenko came about.
“He really is the kind of player that we were looking for,” said Husillos.
“He is a left-footed player but can play on the right and is very quick, very good one-on-one against a defender. He gives the team a lot of attacking options and scores goals, is fast on the counter-attack and provides aerial threat with his height.
“He also has very good experience, of playing for big teams and fighting for titles. At Dortmund, he had some good matches but perhaps didn’t quite show his very best. However, I think Manuel Pellegrini is the perfect coach for Andriy and his style of play.
“I believe he is joining us in the perfect moment. He is 28, the prime age for football, and we have great expectation about what he can achieve with West Ham United.”