West Ham United have completed the signing of former Arsenal midfielder on a three-year deal.
The 26-year-old joins the Hammers on a free transfer after living the Emirates Stadium following the end of his contract in June with the Gunners.
"It feels special. Many people know that I've had a special bond with this club growing up. I've got good memories of my childhood supporting West Ham, watching them at Upton Park," Wilshere said.
West Ham director of football Mario Husillos said: "Manuel and I identified him as a target as soon as we joined the club and we are delighted to have succeeded in securing Jack's signature above a number of other teams."
Wilshere made 197 first-team appearances for Arsenal and was part of the 2014 and 2015 FA Cup-winning squad.
Meanwhile, Borussia Dortmund forward Andriy Yarmolenko has arrived at West Ham's training camp in Switzerland, according to Sky sources.
The 28-year-old joined Dortmund from Dynamo Kiev in August 2017 but struggled to find his best form in Germany, scoring six goals in 26 appearances. He has scored 35 times in 77 appearances for his country
Yarmolenko has begun the first part of his medical ahead of a £17.5m move to the Premier League side.
Meanwhile, the Hammers are willing to sell Michail Antonio this summer and are prepared to consider offers of more than £15m, according to Sky sources.
Sky Sports also report that Manuel Pellegrin's sides are in advanced talks to sign midfielder Felipe Anderson from Lazio.
On the other hand, the Hammers are ready to listen for offers on Michail Antonio this summer and are willing to consider offers of more than £15m.