Colchester have signed Manchester City defender Camron Gbadebo on a short-term deal, and Bradford keeper Sam Hornby and Aston Villa winger Tyreik Wright on loan until the end of the season.
Gbadebo, 19, has previously had a loan spell with non-league Fylde.
Hornby, 27, has made nine appearances for the Bantams this season.
Republic of Ireland Under-21 international Wright, 20, spent the first half of the season on loan with Salford City.
Colchester are 22nd in the League Two table, seven points above the relegation places, and have made 10 signings in January.
Find all the latest football transfers on our dedicated page.