The money will be donated to the San Diego Foundation, Interscope Records said in a statement.
Stefani made the announcement Monday morning on the radio station 93.3 KHTS with San Diego mayor Jerry Sanders.
"San Diego has always been so supportive of me throughout my entire career," Stefani said. "Living in Orange County, it has always been like a second home to me. When I heard about the devastation of the fires, at first, I felt I should cancel my show out of respect, but then it occurred to me there might be a more useful solution."
"We applaud the generosity of Gwen Stefani in dedicating her upcoming concert to support The San Diego Foundation's After-the-Fires Fund 2007, which will help the foundation help San Diego," Sanders added. "I have been heartened by the many who have come forward to assist us in the fire relief effort, and we thank Gwen Stefani and her fans for supporting the fire recovery and rebuilding across San Diego."