Line 5 Eglinton

Line 5 Eglinton, also known as the Eglinton Crosstown LRT or the Crosstown, is a light rail transit line that is under construction in Toronto, Ontario, Canada, that will be part of the Toronto subway system. Owned by Metrolinx and operated by the Toronto Transit Commission (TTC), the line was conceived in 2007 during the administration of Toronto mayor David Miller as part of Transit City, a large-scale transit expansion plan that included several light rail lines proposed across the city. While the plan was later dropped by successive municipal governments, only the Eglinton Crosstown LRT received support and funding from the Government of Ontario under premier Kathleen Wynne.

The line is being constructed in two phases. The first phase of the 19-kilometre (12 mi) line will include 25 stops along Eglinton Avenue, from Mount Dennis station mostly underground to Laird station, after which it will run predominantly at-grade within the street's median to Kennedy station, where it will connect underground with Line 2 Bloor–Danforth. Automatic train control will be used in the tunnelled sections. This first phase has an estimated cost of CA$12.82 billion; the cost when the contract was awarded was pegged at $9.1 billion, although the cost was originally estimated at $11 billion. This phase is incomplete and has no scheduled opening date. A second phase, a 9.2-kilometre (5.7 mi) westward extension from Mount Dennis, will run mostly underground or elevated to Renforth station, with seven new stations. The second phase is expected to cost $4.7 billion and to be completed by 2031. Construction of the westward extension to Renforth station began in July 2021.

Two future extensions were planned: an eastern extension to the University of Toronto Scarborough and a northwestern extension towards Toronto Pearson International Airport. In 2022, the city of Toronto converted the eastern extension into a city project and a separate line known as the Eglinton East LRT using light rail technology incompatible with the Line 5 technology.

Construction of the first phase of the line began in 2011 and was originally expected to be completed in 2020, but the opening date has been revised several times. Metrolinx expected the line to be substantially complete by September 2022 but then conceded it would not meet that date. After revising the opening date of the central section to 2023 and then, amid ongoing legal action against Crosslinx (the construction consortium), Metrolinx stated they believed there was no credible schedule to complete the project. While the central section was estimated to be 97 percent complete in September 2023, Metrolinx refused to provide an estimated completion date, although they did indicate they would provide notice three months before opening. In June 2025, Metrolinx stated that a September 2025 opening was still possible.