The 24-year-old joined West Brom's promotion push in February and has impressed, playing seven times and scoring one goal.
Last week Watson said that he would welcome a permanent swich to The Hawthorns, but Wigan exercised a clause in the contract to recall the former Crystal Palace player within 28 days due to injuries and suspensions.
West Brom manager Roberto di Matteo told the club's oficial website: "We are sorry to see Ben go. He's a great lad and made a vital contribution to our season."
Wigan manager Roberton Martinez said: "In the final six weeks of the season we need to be as strong as we can.
"With the situation regarding Gary Caldwell missing three games and Hendry Thomas facing a short time out it puts added pressure on the squad."
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