Daryl Murphy's second-half strike ensured Ipswich extended their unbeaten home run to eight matches.
The goal came three minutes after the interval when Michael Chopra teed up Murphy and he scored with a left-footed shot from the edge of the box.
Ipswich almost doubled their lead when Jay Emmanuel-Thomas rattled the woodwork from 35 yards before seeing another long-range strike go just over.
Frank Nouble and Craig Davies had shots for the Tykes, but both were saved.
When the sides met at Oakwell in December, Ipswich came back from 2-0 down to win 5-3 in an exciting game.
There was no sign of a repeat on this occasion, with Ipswich showing all the running as the visitors succumbed to fifth defeat in six matches.
Ipswich were largely restricted to long-range shots before the break but Barnsley goalkeeper David Button was only called into action once.
The home side made the crucial breakthrough just after the break when Paul Jewell's side claimed a deserved lead.
Michael Chopra set up Murphy and he found the bottom corner with a left-footed shot.
Emmanuel-Thomas then hit the bar with that remarkable long-range effort.
A beleaguered Barnsley offered little by way of a response, until Nouble and Davies tested Lee-Barrett but he was equal to the challenge on both occasions and Ipswich comfortably saw out the remainder of the game.