The beleaguered Bulls say they need £500,000 by next Friday in order to pay a looming tax bill and avoid the threat of administration. O'Connor's donation, out of his own pocket, helped take the total of pledges past the £100,000 mark inside the first 48 hours and closer to the £1million the club say they need by the end of April to guarantee their survival.
"Steve rang me to offer his support for the situation we find ourselves in - but also to say he wanted to pledge an enormous sum of £10,000," Bradford chairman Peter Hood told the Bradford Telegraph & Argus.
"Steve spoke eloquently at length about the rugby league community and how we are all in this together.
"He talked of the outstanding contribution that the Bradford Bulls have made to the game and he wants that to continue. His heartfelt and extremely generous contribution epitomises the response we have had from throughout the game."
Meanwhile, the Bradford supporters trust, BullBuilder, have urged fans to put aside their lack of confidence in the directors by backing their fund-raising efforts.
"We are satisfied that the situation is one of extreme gravity, which indeed requires an immediate cash injection," they said in a statement.
"After detailed discussions as a committee, we are convinced that it is of paramount importance for the club to raise sufficient funds to avoid administration.
"We believe that administration would, at the least, mean that BullBuilder's efforts in support of junior Bradford Bulls players would have been wasted as other clubs reap the benefits of players already developed and currently coming through the system.
"At worst, there are no guarantees that the Bulls will survive in any form, given that the club's position is unique and not directly comparable to other recent administrations, such as that from which Wakefield emerged last season.
"As a result we urge our members, the fan base and the rugby league community as a whole to support the club's efforts to raise the necessary funds via the pledge and related fund-raising efforts."