Players of both teams wore the number 96 on their tracksuit tops in tribute to those who died.
Liverpool supporters have campaigned for years for "Justice for the 96".
United legend Sir Bobby Charlton carried a bouquet of 96 roses to hand to former top Liverpool striker Ian Rush, and captains Steven Gerrard and Ryan Giggs released 96 red balloons.
Fans applauded in memory of those who died and a mosaic was displayed around three sides of the ground during the traditional playing of Liverpool anthem "You'll Never Walk Alone".
Parties including United manager Sir Alex Ferguson have urged supporters of the clubs, who share one of football's great rivalries to behave, amid concern some of the cruel chants about the Hillsborough stadium tragedy and Munich air disaster which have surfaced in the past could feature again.