The 2 Line, also known as the East Link Extension, is a light rail line serving the Eastside region of the Seattle metropolitan area in the U.S. state of Washington. It is part of Sound Transit's Link light rail system and runs for 6.6 miles (10.6 km) in the cities of Bellevue and Redmond. The initial segment serves eight stations between South Bellevue and Redmond Technology stations and opened on April 27, 2024. The full line is scheduled to open in 2025 and is planned to include 18 miles (29 km) from west to east and serve twelve stations in Downtown Seattle, Mercer Island, Bellevue, and Redmond. The 2 Line will continue through the Downtown Seattle Transit Tunnel and share stations with the 1 Line through to Lynnwood City Center station.

Sound Transit (ST), officially the Central Puget Sound Regional Transit Authority, is a public transit agency serving the Seattle metropolitan area in the U.S. state of Washington. It operates the Link light rail system in Seattle and Tacoma, regional Sounder commuter rail, and Sound Transit Express bus service. The agency also coordinates the regional ORCA fare card system, which is also used by local transit operators. In 2019, Sound Transit services carried a total of 48 million passengers and averaged over 161,000 riders on weekdays.