The 1 Line, formerly Central Link, is a light rail line in Seattle, Washington, United States, and part of Sound Transit's Link light rail system. It serves 26 stations in King and Snohomish counties, traveling 41 miles (66 km) between Lynnwood City Center and Federal Way Downtown stations. The line connects Lynnwood, Mountlake Terrace, Shoreline, the University District, Downtown Seattle, the Rainier Valley, Seattle–Tacoma International Airport, Kent, Des Moines, and Federal Way. The 1 Line carried over 35.5 million total passengers in 2025, with an average of nearly 103,000 daily passengers on weekdays. It runs for 20 hours per day on weekdays and Saturdays, with headways as low as six minutes during peak hours, and reduced 18-hour service on Sundays and holidays.