Tykes goalkeeper Luke Steele brilliantly kept out Darius Henderson's 75th-minute header from Glen Little's corner, while Blades defender Paul Connolly was sent off in the closing stages for a second yellow card.
But there was little else to inspire a near 25,000-crowd in a South Yorkshire derby high in endeavour, but low on quality.
Both sides started the game with just one win in their previous seven league matches and had seen their play-off chances subsequently wane and this stalemate leaves the Blades without a win in their last four games while Barnsley have not won any of their last five.
Blades skipper Chris Morgan, fellow defender Jordan Stewart, Glen Little and Jamie Ward all returned for the home side, while Barnsley recalled Andy Gray, Iain Hume and Luke Butterfield to their starting line-up.
It was the first time Hume and Morgan had faced each other since a collision during the derby between the two sides at Oakwell in November 2008 that had left the Barnsley striker with a fractured skull.
Steele twice denied the Blades in the first nine minutes, first tipping Richard Cresswell's header over the crossbar and then saving smartly from Ward, who had steered a rebound in the six-yard box goalwards.
Ward and Cresswell were off target with two long-range shots as United dominated the first half an hour before the Blades were dealt a double injury blow in the space of 12 minutes.
Stewart succumbed in the 28th minute and was replaced by Andy Taylor and Ward, sidelined for three weeks with a torn hamstring, lasted just 38 minutes in his comeback match before making way for Mark Yeates.
The Blades' momentum was checked due to the disruption and Barnsley pressed forward as half-time approached with Emil Hallfredsson's shot blocked by Nyron Nosworthy and Hugo Colace's 25-yard free-kick held by home goalkeeper Steve Simonsen.
Barnsley stepped up the tempo early in the second half, but Blades substitute Yeates fired a 25-yard shot over the crossbar and then forced Steele into a comfortable save with a curling free-kick.
The visitors enjoyed the lion's share of possession as the game entered the final 20 minutes without fashioning any clearcut chances and it was the Blades who went closest to breaking the deadlock again when Little pulled his shot wide from six yards following a cross from Yeates.
Little then crossed for Darius Henderson, who saw his close-range effort blocked by Barnsley defender Luke Potter and Blades midfielder Nick Montgomery drilled a 25-yard shot just wide as the home side wrestled back control.
Tykes defender Darren Moore performed heroics to block another Montgomery shot and when Henderson powered in a header from Little's 75th-minute corner, Steele pulled off a super save.
The Blades chased the goal that would keep their season alive in the closing stages but fell short in the final third, while late substititions for both sides - Martin Devaney on for Tykes foward Hume and Lee Williamson for Blades winger Little - failed to change the outcome.