The donors, all longtime supporters of the company, are Gerard L. (Jerry) Hanauer, John and Laurel Nesholm and the Nesholm Family Foundation, and Susanne F. Hubbach.
Hanauer has pledged $15 million, two-thirds of which will go to the company's endowment; $4 million of the remainder will be disbursed over four years to support current operations, with $1 million to be bequeathed later. His gift alone will bring the company's endowment to $18.6 million, more than doubling the fund's assets.
Previously a Wall Street trader, Hanauer is now co-chairman of PCFC, the largest U.S. manufacturer of basic bedding.
The Nesholms and their foundation will give $5 million for artisitic initiatives over the next five seasons.
"Seattle Opera has brought our family its most satisfying artistic experiences," said John Nesholm, founding partner of LMN Architects and Seattle Opera's board chair since 2005. He and wife Laurel attended the company's production of Der Rosenkavalier on one of their first dates.
Of the $1.5 million from Hubbach, one-third will go to the endowment and the rest to support annual operations through 2012.
The three gifts amount to the largest sum the company has ever received.
"I am overwhelmed at the generosity of these four donors," said Jenkins.