The Premier League club have been strongly linked with the 21-year-old centre-back throughout the close season, but have distanced themselves from reports saying they were set to open talks with the Blades captain.
Hull's denial comes hours after Sheffield United said they had "reluctantly" accepted an improved offer.
Their statement read: "Sheffield United rejected an offer from the club five days ago (Wednesday) for defender Harry Maguire. This was the club's final offer and we have since entered into discussions with other transfer targets.
"In light of Sheffield United's statement this morning the board will meet with manager Steve Bruce this afternoon to determine whether we now wish to pursue the transfer after the South Yorkshire club's apparent U-turn."
The Blades' earlier statement, which claimed Maguire was free to begin talks at the KC Stadium, read: "Hull have finally met United's valuation for the defender, who has now been granted permission to speak to the East Yorkshire club."
United's managing director Mal Brannigan commented: "We made it clear that we wanted Harry to stay by offering him a new contract at the end of last season, unfortunately he and his representatives chose a different path.
"However, as he is under contract at Bramall Lane, we exercised our right to set our own valuation of him and after numerous bids which did not meet our expectations, Hull City increased their offer and we have reluctantly accepted.
"As we have previously stated, Sheffield United are not under pressure to sell our players but on this occasion it was deemed the best for all parties and now we move on with the aim of assisting Nigel Clough to strengthen his squad."
Maguire has made over 150 appearances since coming through the Blades' academy in 2011.
It later emerged that Hull were preparing a bid for Arsenal’s Carl Jenkinson, who is set to become surplus to requirements at the Emirates after the London club moved closer to signing Southampton’s Calum Chambers.
Initially it was reported that Hull were interested in a straight cash deal for Jenkinson but he could now make a loan switch to the KC Stadium.
- Sports & Recreation
- Sheffield United
- Harry Maguire