The 20-year-old striker spent last season with Brighton, helping the Seagulls to the Championship play-offs with five goals in 28 outings.
Wilson's last Premier League appearance for United was in October 2015.
"He is an energetic player who will add to our existing attacking options," Derby manager Nigel Pearson told the club website.
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James Wilson has joined Championship side Derby on loan from Manchester United for the rest of the season.