Washington State Route 515

State Route 515
A map of Kent and Renton with SR 515 highlighted in red
Route information
Auxiliary route of I-5
Maintained by WSDOT
Length	7.86 mi[1] (12.65 km)
Existed	1964–present
Major junctions
South end	SR 516 in Kent
Major intersections	I-405 in Renton
North end	SR 900 in Renton
Location
Country	United States
State	Washington
County	King
Highway system
State highways in Washington Interstate US State Scenic Pre-1964 1964 renumbering Former
← SR 513 → SR 516

State Route 515 (SR 515) is a state highway in the U.S. state of Washington serving suburban King County. The highway travels 8 miles (12.9 km) north from SR 516 in eastern Kent to Renton, where it intersects Interstate 405 (I-405) and SR 900.

The highway was originally built by the county government in the 1910s as a winding gravel road connecting local coal mines. It was straightened and paved in the 1920s and was designated as Secondary State Highway 5C (SSH 5C) in 1937. SSH 5C was replaced by SR 515 in the 1964 state highway renumbering and extended north into downtown Renton after the construction of I-405. A section of the highway on Talbot Highway was moved to a new bypass road in 1982 and other sections in Kent were widened to four lanes in 1991. The I-405 underpass was rebuilt as a half diamond interchange in 2010.