The Seattle Monorail is an elevated bridge-girder monorail line in Seattle, Washington, USA. The 1.4 km long monorail runs along 5th Avenue between Seattle Center and Westlake Center to downtown Seattle, with no intermediate stops. The monorail is a major tourist attraction, but it also operates as regular public transportation, with trains running every ten minutes up to 16 hours a day. It was built in eight months and cost $4.2 million for the 1962 Century 21 Exposition, a world’s fair held at Seattle Center. The monorail underwent an overhaul in 1988 after the south terminal was moved from Pine Street inside the Westlake Center Mall.

The system will retain its original fleet of two Alweg trains, each carrying up to 450 people and was designated a historic landmark by the city in 2003. owned by the city government and operated by a private contractor since 1994, when it replaced King County Metro, the county’s public transit system. The system serves about two million people each year and generates a profit that is shared between the contractor and the city government. The monorail usually operates with one per track, and the entire trip takes about two minutes. There have been several accidents in the half-century of operation of the system, including a train collision in 2005 caused by a gauntlet installed during the 1988 reconstruction near the Westlake Center terminal.

Several government agencies and private companies have proposed extensions of the monorail system since its inception in the 1960s. The most notable of these was the Seattle Monorail Project, founded in 1997 as part of a ballot initiative to create a citywide network that extended coverage beyond the planned Link system. The project ran into financial difficulties, including cost estimates rising to $11 billion before it was canceled by a city vote in 2005.

The 1.4-kilometer monorail begins from the terminal at Seattle Center, a public complex and park located northwest of Seattle Center. The Seattle Center Terminal is located at Next 50 Plaza near the center of the complex, next to the Space Needle, Chihuly Garden and Glass, and Memorial Stadium. It towers over the south end of the plaza and consists of three platforms, using the Spanish solution: two side platforms for drop-off and a central platform for boarding. The monorail service point is located below the platforms at Seattle Center Station at ground level. From the terminal, the tracks run east and begin to widen a southbound turn, passing through the Pop Culture Museum, which was designed around the new tracks.

The monorail tracks intersect. Broad Street and go two blocks on the outside of 5th Avenue North, passing the KOMO Plaza Broadcasting News Center. The tracks then launch a southeast turn through a small office building and auto shop toward 5th Avenue, which starts at South Denny Way and Tilikum Place. The street runs southeast through Belltown as a one-way street with southbound traffic only, which is divided into two groups of passing lanes by supporting monorail columns. The monorail passes several city sites, including the Amazon Spheres and Westin Seattle towers, and ends up in McGraw Square, where 5th Avenue turns slightly south. Before reaching the south terminal of the Westlake Center Mall on Pine Street, the monorail tracks taper into a set of gloves 4 to 5 feet (1.2 to 1.5 m) apart, preventing two trains from using the station at the same time. The Westlake Center terminal is located on the third floor of the Mall and has direct access to street level and the Westlake Tunnel Station, which is served by Link Light Rail trains. The South Lake Union Streetcar also stops at nearby McGraw Square, and several major bus routes pass near the Westlake Center Terminal.