Both the Blades and the Owls have united in a joint sponsorship deal, worth a six-figure sum to each club, with Sheffield companies Westfield Health and motor sales group Gilders and will wear identical logos on their shirts.
Blades chairman Kevin McCabe said: "Sheffield is very proud of its footballing heritage and with this deal the city has added yet another first to the history books. Sheffield United is eagerly anticipating working with two such reputable Sheffield-based companies, who we know well, in the season ahead."
Wednesday Chairman Milan Mandaric added: "This is an exciting partnership for all concerned and will further develop as the season progresses. I'm new to this city, but have quickly recognised the importance of working with two organisations who are Sheffield through and through."
The Blades' three-year deal with previous sponsors the Maltese Tourism Authority expired this summer, while the Owls donated their shirt sponsorship to the Sheffield Children's Hospital two years ago.