Atkinson has made seven first-team appearances for Hull, including four this season.
He also has Premier League experience after turning out for the Tigers against Wigan, where he scored, and Liverpool in 2010.
The 22-year-old, who has had loan spells at Port Vale in 2007, Mansfield 2008 and Rochdale in 2009 and 2010, will stay with the Millers until January 4.
Source: PA
Source: PA