Newcastle

Newcastle, Washington, is an Eastside city in King County, nestled between Bellevue and Renton, offering a blend of suburban tranquility and urban convenience. As of 2026, its population is estimated to be around 13,035. Known for its scenic beauty and vibrant community, Newcastle provides residents with a peaceful atmosphere, a short commute to major work centers, and easy access to both recreation and urban amenities. Historically a significant coal mining area, Newcastle played a crucial role in the development of Seattle and the surrounding region. Today, while maintaining its residential character, Newcastle's economy is supported by technology, healthcare, retail, and education sectors. The city is experiencing new development, offering opportunities for prospective and existing businesses. What makes Newcastle distinctive is its rich history, memorialized in place names like Coal Creek, and its commitment to preserving open spaces and providing recreational opportunities. With nearly 40 acres of developed parks and a well-developed trail system, including access to Cougar Mountain Regional Wildland Park, Newcastle offers a high quality of life for its residents.