The centre-back has been heavily linked to a move to the English side over the past few years, having been a key player for Dortmund as they won two consecutive Bundesliga titles then reached the Champions League final in 2013.
British media outlets have claimed Hummels promised Ferguson back in 2012 - when the former coach attended the DFB-Pokal final against Bayern Munich - that he would join the Old Trafford club.
The defender, though, denies any such commitment to leaving Dortmund for Old Trafford and dismissed it as completely made up.
"To clarify: this supposed "promise" is simply fictitious... And that's the polite way of putting it," Hummels tweeted.
The World Cup winner, who has been at Dortmund since joining from Bayern Munich on an initial loan deal in 2008, is contracted to the club until 2017.