A substantial milestone has been reached in the construction of Ontario Line 3 as Metrolinx announced the completion of excavation at the future site of King-Bathurst station on February 12th. Located at the western edge of Toronto's Entertainment and Fashion Districts, the station will sit 40 metres below street level and put 27,000 nearby residents with walking distance of subway service.

The interior of the now completely excavated King-Bathurst station, image courtesy of Metrolinx

In September, 2024, as the name suggests, work on King-Bathurst station began deep under the intersection of King Street West and Bathurst Street. At the junction of the highly urbanized King West, Niagara, and West Queen West neighbourhoods, the future station will serve over 5,000 riders per hour at peak times. Many of these passengers will transfer from the intersecting 511 Bathurst and 504 King streetcars, the latter of which is the busiest streetcar route in the network, carrying over 60,000 riders each day.

A diagram of the alignment and future station entrances of King-Bathurst station, image courtesy of Metrolinx

Due to the dense cluster of commercial, residential, and mixed-use buildings around the intersection, as well as the offset nature of the station's alignment with the street grid, a careful subterranean surgery has been necessary to carve out the space for the future facilities. Consequently, the northeast and southeast corners of King and Bathurst have been occupied by expansive shafts that provide access to the tunnel route dozens of meters below street level. Digging through countless tons of soil, clay, and bedrock is further complicated by over a century of accumulated municipal infrastructure, the exact location of which is not always known at the start of construction.

Looking east over the intersection of King Street West and Bathurst Street in July 2025, with work on King-Bathurst station already consuming the eastern corners of the crossing, image courtesy of UrbanToronto forum contributor Kotsy

Despite these complexities, work has progressed smoothly since ground breaking occurred in late 2024. An image from a June, 2025 Metrolinx Construction Liaison Committee meeting highlights the significant progress made within the first nine months of excavation.

Looking southwest along the still under-excavation King-Bathurst station shaft in June 2025, image courtesy of Metrolinx

In the subsequent eight months, all excavation work has been completed, and now the years long process of installing the complex web of ventilation shafts, rail signalling infrastructure, subway tracks, elevators, escalators, passenger mezzanines and platforms can now get underway. 

Within the now fully excavated station site, workers begin to construct formwork to allow the pouring of concrete that will make up the structure of the station's interior facilities, February 2026, image courtesy of Metrolinx

While this work is being performed, preparations must also be made for the arrival of the twin tunnel boring machines (TBMs) that will burrow the majority of the Ontario Line’s right-of-way through the downtown core. These machines are set to be launched in the Spring of this year from a now-complete tunnel portal at Exhibition Station, located west of Strachan Avenue.

After tunnelling just over a kilometre of Line 3's below-grade alignment east of Exhibition station, the TBMs will breach through the South Headwall of King-Bathurst station. Once within the station site, they will be carefully manoeuvred through the station towards the North Headwall, before once again being launched towards Queen-Spadina station, where a similar process will be undertaken. 

Workers install formwork to allow for the pouring of concrete structures that will one day form a part of the station's platforms and track beds, February 2026, image courtesy of Metrolinx

Years of work remain, but this announcement marks a significant step in the construction of Toronto's decades-overdue subway through the downtown core. In due time, local residents and transferring streetcar riders will be able to board automated subway trains arriving as frequently as every 90 seconds. This will allow them to reach destinations such as Liberty Village, the Financial District, Leslieville, and Flemingdon Park in a mere fraction of the time these trips currently take on transit or in private vehicles.

A rendering of the currently under-construction King-Bathurst station, image courtesy of Infrastructure Ontario

UrbanToronto will continue to follow progress on these developments, but in the meantime, you can learn more about them from our Database files, linked below. If you'd like, you can join in on the conversations in the associated Project Forum threads or leave a comment in the space provided on this page.

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UrbanToronto's research and data service, UTPro, provides comprehensive data on construction projects in the Greater Golden Horseshoe—from proposal through to completion. Other services include Instant Reports, downloadable snapshots based on location, and a daily subscription newsletter, New Development Insider, that tracks projects from initial application.​