The Tigers were dominant throughout and may consider themselves unfortunate not to have won by a more handsome margin.
Robert Koren twice came close to making Hull's lead more comfortable but was denied by Steele after having previously having seen his shot blocked for a corner.
Barnsley's first real sight of goal came after the interval but Stephen Dawson blasted off target from a good position.
The majority of the chances continued to fall for Hull, but Jay Simpson's attempted overhead kick sailed harmlessly over the crossbar, while Liam Rosenior's tame curling effort was held comfortably by Steele.
Simpson and Ahmed Elmohamady both had late chances to make the result more emphatic but Hull had to be content with a 1-0 win that keeps them in the playoff places.