Schwarzenegger said he signed the environmental exemption bill last week but saved the announcement for a press conference in Industry, where the stadium would be built about 15 miles east of Los Angeles.
The bill would nullify a lawsuit filed by residents in nearby Walnut over the project's environmental impact.
Schwarzenegger called the lawsuit frivolous as he addressed a crowd of union members wearing hardhats. Across the street, a dozen protesters held signs saying "No Stadium."
"This is the best kind of action state government can create -- action that cuts red tape, generates jobs, is environmentally friendly and brings a continued economic boost to California," Schwarzenegger said.
Majestic Realty Co. is heading the stadium project after helping develop Staples Center, the downtown Los Angeles home of the NBA's Lakers and Clippers and the NHL's Kings.
Majestic has targeted seven teams as candidates to move to the Los Angeles area: the Buffalo Bills, Jacksonville Jaguars, Minnesota Vikings, St. Louis Rams, San Diego Chargers, Oakland Raiders and San Francisco 49ers.
The firm has said the teams are in stadiums that are either too small or can't be updated with luxury box seats or other revenue sources an NFL club needs to thrive.
Schwarzenegger said the stadium would generate more than 18,000 jobs.
Majestic guaranteed parking lot attendants and concession stand workers would be paid middle-class wages, said Maria Elena Durazo, head of the Los Angeles County Federation of Labor.
"This is true economic development," Durazo said. "It's going to benefit everyone in our community."