The 21-year-old, who is the younger brother of Sunderland defender and former United player Wes, has already had a temporary spell at Coventry this season.
Brown has also been loaned out to Oldham, Bradford and Doncaster in the past.
But he will now concentrate on helping Mick McCarthy's side move away from the Championship relegation zone, while also earning valuable first team experience at Portman Road.
"This is a big challenge for me and I'm excited to be signing for Ipswich," Brown told his new club's official website.
"It's a big club with great facilities and I'm looking forward to meeting all the lads and getting started.
"I've played here once before - in an U15 Academy showcase game for United - so it's nice to be back here again and I'm ready to try and prove myself at Ipswich.
"I'm still only 21 and getting experience at a Championship club like Ipswich is good for me and it's all part of my education."