Mosqueda confirmed to serve on Sound Transit Board

December 9, 2025

King County Councilmember Teresa Mosqueda was unanimously confirmed Tuesday as a new member of the Sound Transit Board of Directors, taking on a central role as the agency enters a decade of major decisions that will shape how the entire region moves for generations. 

Mosqueda, who represents District 8—including West Seattle, portions of Downtown and Capitol Hill, Chinatown-International District, SoDo, and surrounding neighborhoods—joins the board at a time when Sound Transit is advancing extensive light rail expansion plans, including the highly anticipated West Seattle Link Extension. The project will bring fast, frequent, and reliable transit to some of the region’s densest neighborhoods and set the stage for future opportunities for further light rail expansion—but it also carries significant financial and transit planning considerations. 

With costs rising and design decisions approaching, Mosqueda’s presence on the Sound Transit Board ensures that families, workers, small businesses, and transit riders across these diverse communities—each with distinct needs and priorities—have a strong advocate at the table. This is in part why she was nominated to serve on the board by King County Executive Girmay Zahilay late last week. 

“Light rail is a powerful tool for economic empowerment, equitable growth, and community self-determination—and maintaining momentum on Sound Transit expansion is essential to deliver on this vision for communities across King, Pierce, and Snohomish Counties," Mosqueda said. "I’m honored to take on this responsibility at such a critical moment. I’ll be focused on making sure the project moves forward in a way that helps reduce overall costs, creates equitable and affordable access to neighborhoods, supports workers and complements existing amenities, and builds the connections our communities can depend on.” 

Mosqueda brings experience in public health, labor policy, housing, and economic justice—fields closely tied to how major transportation projects shape communities. She has long championed transparency in public budgeting, equitable access to services, housing abundance and affordability, and strong community engagement—priorities she says will guide her work on the board. 

“Delivering on this generational investment will require strong partnership across jurisdictions, stakeholders, and communities,” Mosqueda said. “I will prioritize building and strengthening coalitions with labor, local businesses, environmental, housing, and community partners to strengthen regional collaboration and enhance communication so that Sound Transit can deliver a high-capacity transit system that serves all of our communities.”   

Mosqueda will begin serving on the Sound Transit Board immediately with her first meeting on December 18. She joins three other newly confirmed members including King County Councilmember Steffanie Fain, Seattle Mayor-Elect Katie Wilson, and Tukwila Mayor Thomas McLeod.