He is on his way to League Two side Chesterfield on a three-month-long loan. Chesterfield was where Super Kev really got his start, spending four seasons there after making his debut for the Spireites at just 16.
O'Halloran was on loan once already this year, to League One side Carlisle United but that stint lasted only 12 days. Carlisle manager Greg Abbot said this about the situation back in September:
"Michael came to see me and he told me that he felt that he wanted to get back down to Bolton to carry on his work down there.
"He wanted more in the way of pitch time with us and we couldn't guarantee him that at this moment in time. I spoke to Owen [Coyle] and he has been fantastic about the situation, so Michael leaves here with our very best wishes."
O'Halloran still has not made a competitive league appearance for Bolton but did make his debut last year in the League Cup against Macclesfield Town. He made seven loan appearances for Sheffield United at the tail end of lat season but failed to score a single goal. He signed a 3.5 year contract extension last winter.