The 23-year-old attacking player has signed a three-and-a-half-year contract with the option of a further 12 months and becomes Tony Pulis’ first signing at Albion.
“I???m delighted we???ve got Callum and I believe he will be an exciting addition to our numbers,??? Pulis told the club website. “Callum is a player who can improve our options and I am really looking forward to working with him.”
McManaman leaves Wigan almost five years – and one FA Cup winners’ medal – since making his first-team debut as a teenager.
He said: “I’m really made up to have joined. When the chance came to move to West Bromwich Albion, and return to the Premier League, I couldn’t turn it down.
“This is a great move for me and I hope the Albion fans will get to see the best of me. Albion are a great club, with a good tradition. I can’t wait to get going.”
McManaman’s departure comes on the same day Wigan sold midfielder Adam Forshaw to Middlesbrough.
Manager Malky Mackay said: “Callum is a fantastic talent and again we found ourselves in a position of having to make a decision regarding a major player in our squad.??
“There???s been a lot of interest in Callum over the last few weeks, but I have made it clear that we need a squad of hungry players who are 100 per cent focused and committed to the job here.
“There comes a point where you have to do what???s best in terms of the player progressing in his career and what is financially the most beneficial for the club.”