It is the first time in its 102-year existence that Subiaco Oval has been rebranded, after the Subiaco council blocked a $5 million bid from mobile phone retailer Crazy Johns in 2003.
WA Football Commission chief executive Wayne Bradshaw confirmed the new name on Friday, describing the deal as a "commercial reality" that will benefit grassroots football in WA.
"We think it's inevitable that the stadium will need to go down the naming rights path, and from our perspective we're trying to deliver community benefit," Bradshaw said on Friday.
"We've been looking for a number of years to achieve a naming rights sponsor and we're very pleased to do so with a sponsor of the calibre of Patersons.
"The naming of Patersons Stadium is a commercial reality that allows the WAFC to deliver community benefit by providing funding to grassroots football."
Bradshaw acknowledged Subiaco Oval's history, but said the move would eventually receive support once the WAFC's motivations were understood.
WA Football Hall of Fame members Barry Cable, Garry Moss, Ron Alexander and Steve Malaxos, as well as both Western Australian AFL clubs, were present on Friday to show their support for the naming rights deal.
"There are those that would like to keep the name Subiaco Oval," Bradshaw said.
"However, as reflected in the support today, we believe that once people understand that the funds are being applied to grassroots football, they'll understand our motivation.
"History is important, but this move is about creating the future."
Bradshaw declined to reveal the amount Patersons Securities was committing to the deal, but it has been reported to be $3.5 million over the four-year term.
Bradshaw said the length of the deal was dictated by uncertainty surrounding the future of the stadium, with a redevelopment, rebuilding or a new stadium at a new site all being considered by the state government.
"Whatever happens, Subiaco will change significantly," he said.
"We're all seeking a better outcome in relation to the new stadium, whether that be a redeveloped Subiaco, a rebuilt Subiaco, or at another venue.
"Our aim out of this sponsorship is to have an enduring partnership with Patersons so it can be entrenched as Patersons Stadium.
"One of the considerations that we had in determining the term is a realisation that there may be a stadium change in the future."
Both Bradshaw and Patersons Securities chief executive Michael Manford were confident the Subiaco Council would allow sufficient signing for the ground.
"There's a significant amount of internal signage and we're talking about a relatively small amount of external signage," Mr Manford said.
"We feel quite confident that the West Australian Football Commission will pursue that objective appropriately."
