The 20-year-old, who has impressed with the Championship club's Under-21 development squad, will be available for selection ahead of Saturday's game against Chesterfield.
Blues boss Paul Sturrock told the clubs official website: "He's a bright player and we hope we can help him improve as a player. We've been looking at him for a while so we're very pleased to have got him here until the end of the season."
The youngster represented Canada at Under-17 level before opting to represent Northern Ireland at Under-19 and Under-21 level.
On joining Southend for the remainder of the season he told the clubs official website -"I'm delighted to have come here to Southend. I'm really looking forward to getting started and getting some professional games under my belt.
"Hopefully I can help Southend in their bid for promotion and I can improve and develop my game while I'm here."