Daryl Murphy’s fourth goal of the season wasn’t enough to give Town the points in front of the biggest crowd of the season at Portman Road.
The Republic of Ireland international headed home four minutes before the break but Barnsley levelled midway through the second-half when Jim O’Brien sidefooted home from close range.
Mick McCarthy named an unchanged side for the seventh successive game, with Paul Taylor the only new recruit on the bench with the striker returning from his loan spell at Peterborough.
After a tame opening 15 minutes, Dean Gerken had to be quick off his line to smother the danger from Marcus Pedersen, while at the other end David McGoldrick couldn’t gather Ryan Tunnicliffe’s cross in his stride.
Tommy Smith, sporting a bandage after sustaining a cut above his eye after a clash with Chris O’Grady, beat Jack Butland to the ball but headed just over, then Paddy McCourt’s effort from 40 yards was cleared by Aaron Cresswell with the goal open as the game came to life.
Butland pushed Cresswell’s cross behind at his nearpost after McGoldrick’s touch, the corner cleared by Martin Cranie as Smith challenged.
Town kept possession well in a move involving five players before Cresswell fizzed a shot across goal after McGoldrick had escaped in the box, Luke Chambers then heading over from Paul Anderson’s corner.
The opener came just before the break and in such a simple way, Cresswell’s corner was met by Murphy, who lost his marker with ease and the striker thumped home a header to give Town a deserved half-time lead.
Gerken saved well to his right from O’Grady as the second-half got underway, O’Brien, on for Jacob Mellis, then firing over as the Tykes looked for a way back into the game.
Cole Skuse volleyed wide from 30 yards, then McCourt released Pedersen in the box but his shot was well over.
Town made a first change on 67 minutes, with Anderson making way for Jay Tabb but seconds later Barnsley were level, Blues failing to clear the cross and O’Brien sliding the ball past Gerken.
O’Brien sent an ambitious effort over from distance as the Tykes continued on the front foot, Murphy heading over in response.
Jason Scotland entered the fray for the final 20 minutes to a warm ovation from the home fans, replacing Pedersen.
The Trinidad international was immediately in the action and it took a terrific tackle from Christophe Berra to keep out his left foot strike after he got clear on goal.
Chambers saw a screamer ping back off a relieved Butland and past the onrushing Tabb, Cranie hacking clear, then Berra did well again to block out Scotland on the edge of the box.
Town made a double change for the last 10 minutes, Tunnicliffe and McGoldrick replaced by Frank Nouble and Taylor.
Scotland had a great chance to put the visitors ahead five minutes from time but dragged his shot into the sidenetting after he was left free at the far post, then O’Brien wasted an even better opening eight yards out.
Town could have won it right at the end when Tabb struck goalwards and Nouble was inches away from diverting the ball home, with Nouble then appealing for a penalty when he went down under a challenge but referee Andy D’Urso waved away Blues’ protests before bringing the game to a close with honours even.