The Tykes' reward for their victory over Burnley last time out is an Oakwell showdown with Sir Alex Ferguson's troops.
Arsenal will tackle Liverpool at Emirates Stadium as two of the Premier League's biggest clubs go head-to-head.
Manchester City will have high hopes of progressing to the quarter-finals after being drawn against Championship side Scunthorpe at Eastlands.
Blackburn Rovers are also up against lower league opposition, with Peterborough United the visitors to Ewood Park.
Tottenham will tackle Everton at White Hart Lane, while Chelsea welcome Bolton Wanderers to Stamford Bridge.
Sunderland, who saw off Birmingham in the last round, face Midlands opposition once again with Aston Villa making the trip to the Stadium of Light.
Struggling Portsmouth will hope for more cup cheer when they come up against Stoke City at Fratton Park.
Carling Cup fourth round drawBlackburn Rovers v Peterborough United
Manchester City v Scunthorpe United
Tottenham Hotspur v Everton
Barnsley v Manchester United
Chelsea v Bolton
Sunderland v Aston Villa
Arsenal v Liverpool
Portsmouth v Stoke City
Ties to be played in week commencing 26th October