Hunt joined the Millers in the summer after leaving Preston but he has been restricted to nine appearances this season and last featured as a substitute in November's 3-2 defeat to Wycombe.
Rotherham boss Steve Evans has sanctioned the move so Hunt - who made 161 appearances across 10 seasons at Bolton - can benefit from the opportunity of much-needed match practice.
Stanley counterpart Leam Richardson is delighted to have the 29-year-old on board to fill his team's problem position of right-back.
"Nicky's got vast experience and he's played at every level in the Football League," Richardson told Accrington's official website.
"It's been a position that we've been crying out for all year. People have been in there and done a good job but right-back is a position I'd identified that we needed to fill.
"With Nicky's experience and his quality going forward and defensively hopefully we've filled that gap.
"He's a player I targeted quite early on and he was really eager to come and play for Accrington Stanley.
"He's been in touch wishing us luck and really showed a hunger to come and play for us. I really, really like that in a professional."
Hunt, who also counts Birmingham, Derby and Bristol City among his former clubs, goes straight into the Accrington squad to face Chesterfield on New Year's Day.