"Destiny's Child -- Love Songs," a greatest-hits CD set for release Tuesday, will feature the song "Nuclear," the first new recording by the vocal group in eight years.
The album sparked reports that the three will reunite on stage when headliner Beyonce performs the Super Bowl halftime show next month.
But Williams told WRUG Media the buzz about an upcoming reunion is not true.
"I'm going to be in the musical 'Fela!,'" she said, referring to the stage production's upcoming world tour. "I hate to disappoint the people and tell them that it's not true. ... I'm so sorry. I'm so sorry."
Notable deaths of 2014 [PHOTOS]
S Club 7 to reunite for BBC charity event