Before European settlers arrived in the 1870s, this plateau and its namesake lake belonged to a constellation of Coast Salish peoples: the Duwamish, Suquamish, Snoqualmie, Snohomish, and the Sammamish themselves. They lived in longhouse villages at seven locations on and near the lake shore, two of them within what is now city limits. The name Sammamish derives from the Lushootseed word for willow, combined with a suffix meaning people. Linguist T.T. Waterman offered an alternative interpretation: meander dwellers, perhaps describing how the Sammamish River winds through their territory.

For most of its recorded history, the Sammamish Plateau remained unincorporated King County, a rural expanse of farms and forest. The Sunny Hills neighborhood arrived in the 1960s, followed by an elementary school. But incorporation didn't come until 1999, making Sammamish one of Washington's youngest cities. The city annexed Klahanie in 2016, pushing its population past 67,000. Today, more than a third of residents are Asian American, and nearly a quarter of households speak Asian or Pacific Islander languages at home. CNN Money consistently ranked Sammamish among America's best places to live throughout the 2000s and 2010s.

The city approved plans in 2008 for a denser town center with mixed-use zoning and taller buildings, but the largest phase stalled for over fifteen years as residents debated how much development their community should absorb. Construction finally began in 2024 on new townhomes, with 600 market-rate apartments planned to follow. Meanwhile, Sammamish's climate action plan works to protect Chinook salmon in local streams, preserve wetlands, and plant trees to counter rising temperatures. The tension between preservation and growth defines modern Sammamish.