The two clubs have agreed a deal that will take the defender to Portman Road in time to aid Mick McCarthy's side and their bid to remain clear of the relegation zone.
After spending the first part of the season with Coventry City, the versatile centre-back has made five appearances at Under-21 level for the Reds.
Brown, younger brother of Sunderland's ex-United star Wes, has represented England at Under-19 and Under-20 level.
"This is a big challenge for me and I’m excited to be signing for Ipswich," Town's new No21 told Ipswich Player.
"It’s a big club with great facilities and I’m looking forward to meeting all the lads and getting started."