State Route 529 is a Washington state highway that connects the cities of Everett and Marysville. The 7.88-mile-long (12.68 km) roadway extends north from an interchange with Interstate 5 (I-5), numbered exit 193, past the western terminus of U.S. Route 2 (US 2), its spur route, Downtown Everett and Naval Station Everett to cross the Snohomish River onto Smith Island. After crossing the Steamboat Slough, the road encounters an interchange with I-5, numbered exit 198, before crossing the Ebey Slough and entering Marysville. In Marysville, SR 529 ends at SR 528. Before being realigned in 1991, SR 529 started at exit 192 of I-5 and traveled north as Broadway through Downtown Everett to Marysville.

Marysville is a city in Snohomish County, Washington, United States, part of the Seattle metropolitan area. The city is located 35 miles (56 km) north of Seattle, adjacent to Everett on the north side of the Snohomish River delta. It is the second-largest city in Snohomish County after Everett, with a population of 70,714 at the time of the 2020 U.S. census. As of 2015, Marysville was also the fastest-growing city in Washington state, growing at an annual rate of 2.5 percent.