Eastwood played 22 League Two games for Bradford City during a loan spell at Valley Parade this season.
U's boss Chris Wilder told the club website: "He is only a young lad but he's hungry to do well and we're sure he'll prove a valuable asset."
Eastwood has represented England at Under-18 and Under-19 levels.
He made one first team appearance during his time at Huddersfield.
Source: BBC Sport
