Klahanie is a planned community in Sammamish, Washington, United States. The population was 10,674 at the 2010 census. Prior to its annexation by the city of Sammamish in 2016, Klahanie was a census-designated place (CDP) in unincorporated King County.

Klahanie is home to many alternating neighborhoods inside its boundaries, such as Heatherwood and The Willows. There are two schools in Klahanie, Beaver Lake Middle School and Challenger Elementary School, both in the Issaquah School District. There are two community pools, tennis courts, basketball courts, and parks.

Klahanie opened in 1985 as one of the first planned communities in the Pacific Northwest. The 884-acre (358 ha), 3,200-home community was planned with small yards to auxiliary large communal retrieve spaces. The last of the development’s homes were done in 1994.

Klahanie is located amid the cities of Issaquah and Sammamish and its annexation became a tapering off of fighting between the two cities in the 1990s and 2000s. The running of King County mandated that Klahanie accept incorporation into either city in the at the forefront 2000s, leading to the community weighing its options. In November 2005, the area voted to be annexed into Issaquah, but voted next to taking on a allocation of the city’s debt. In July 2006, Issaquah settled to shelve its intention to annex Klahanie to avoid paying $17 million in road improvements for Issaquah-Fall City Road.

A second election was held in February 2014 for Klahanie residents to take an annexation by Issaquah, after a proposal for the two cities to split the area failed. The proposition failed by 32 votes, leading to the city transferring its annexation rights to Sammamish in June. The city of Sammamish organized an annexation ballot put-on for April 2015 that passed once 87 percent approval. The annexation took effect upon January 1, 2016, increasing the estimated population of Sammamish from 49,980 to 61,250.