The Owls announced that the club has sold all of its tickets for the eagerly awaited fixture at Bramall Lane on January 12.
A club spokesman said: "Wednesday will head to Bramall Lane with a sold out allocation of 2,220."
Supporters who have missed out can now request to go on the reserve list by emailing [email protected] with their customer ID number, Ticket Priority Point details and contact numbers.
Should any tickets be returned, the club contact those on the reserve list.
Meanwhile, tickets for Blades season ticket holders went on sale this morning.
Any remaining tickets for Blades fans will go on general sale from January 3 to customers registered on the United database with a minimum of 500 loyalty points.
Tickets are priced from £30 adults, £25 Seniors, £20 Young Adults/Students and £15 juniors.
All areas of the ground including the Westfield Corner and Redbrik Upper Tier are available to home supporters. Visiting supporters will be allocated the Redbrik Lower.
Tickets can be purchased in person at the Ticket Office, over the telephone on 0114 253 7200 or securely online.