Early proposals In March 2007, Toronto mayor
David Miller announced the Etobicoke–Finch West LRT as part of the
Transit City project to build several light-rail lines within the city. In March 2010, the Ontario government budgeted less for building transit. As a result, it eliminated the proposed section of the line east of Finch West station. However, in February 2012, city council voted to restore the project, along with the
Eglinton Crosstown LRT (later renamed Line 5 Eglinton), as part of a new transit plan, restoring some of the elements of the Transit City proposal over Mayor Ford's objections. In April 2012,
Metrolinx proposed to start construction on the Finch West LRT in 2015, with the line opening in 2018. In May 2017, Metrolinx confirmed that it had entered into an agreement with
Alstom to build 17 (later revised to 18) In September 2017, Metrolinx announced the line would not open until 2022 at the earliest, blaming the delay on uncertainty with the
Bombardier vehicle supply. In April 2018, Mosaic Transit Group was selected to build the transit line. After consultation with Mosaic on a construction schedule, Metrolinx delayed projected completion of the line to 2023, ten years after the originally announced date. That May, Infrastructure Ontario and Metrolinx announced that Mosaic had signed a contract to design, build, and finance the construction of the line and stations, and to maintain them for 30 years after their initial opening. Effective June 20, 2021, the TTC renumbered the Bay bus route in
downtown Toronto from 6 to 19 to free up the route number 6 for the Finch West line. In 2023, the estimated cost of the line was . As of March 31, 2025, the budgeted cost of the line was $3.585billion. Other utility work followed, with replacement and relocation of watermains, hydro poles and hydro cables. In the second quarter of 2019, substantial construction of the project began with work on the
maintenance and storage facility (MSF). Major construction by Mosaic Transit Group began in 2019. In June 2020, the
Highway 400 overpasses over Finch Avenue were removed and replaced over two consecutive weekends, using a "rapid bridge replacement" technique. This involved moving the old overpass aside in one piece and installing a new overpass in its place. By late October of that year, the first rails were being installed at the line's new maintenance and storage facility, with the first vehicles scheduled to arrive in mid-2021. Bombardier was also chosen to maintain the fleet and wayside systems for Line 5 Eglinton in a different contract. In January 2021, the first of 11 traction power substations to power the trains was installed. This substation would power an initial section of track between Norfinch Road / Oakdale Drive and Sentinel Road to allow for train testing. In February 2022, an LRV made a trip from the MSF along York Gate Boulevard onto Finch Avenue. By May 2022, Mosaic Transit Group had laid about 35 percent of the of the total track required to complete the line. Besides the double-track mainline, the total track to be laid included crossovers, pocket tracks, and MSF trackage. By September 1 of that year, 47 percent of mainline track had been laid. By November, the first eight of 116 platform canopies and the first two of 29 electrical cabinets to power lights, fare machines, and security systems along the line were installed at the Driftwood stop. By March 2023, 56 of the 116 canopies were installed, 75 percent of the catenary poles were installed and 50 percent of the mainline track had been laid. By October, all rail and overhead catenary had been installed, and all 18 light-rail vehicles had received their final acceptance. By November, all platform canopies had been installed. In May 2024, the first light-rail vehicle made a test run along the entire line, from Finch West station to Humber College station, with speeds up to . By September of that year, construction was complete for all stations and stops, with only the testing and commissioning phase remained to be completed. On August 15, 2024, Mosaic Transit Group filed a lawsuit against the provincial government alleging that when the Toronto Transit Commission was designated as the line's operator, some terms in an agreement between Metrolinx and Mosaic were violated. Mosaic alleged that the agreement between Metrolinx and the TTC was interfering with the completion of the line. Mosaic expected the TTC to "facilitate effective implementation of maintenance and operational requirements once the line commences service". Back in July 2023, it was expected that Line 6 would open within the first half of 2024, but by December 2023, the TTC made the assumption for budget purposes that the line would open no earlier than September 2024, although the builder, Mosaic Transit Group, expected the line to open by the end of that year. But by early December 2024, Councillor
Jamaal Myers, chairman of the TTC board, stated that the commission did not expect opening before June 2025 at the earliest.
Testing and implementation on opening day, December 7, 2025 In early September 2025, Metrolinx transferred operational control of Line 6 to the TTC. The TTC's transit control centre at the
Hillcrest Complex became responsible for the line's operation. Mosaic Transit Group continued to maintain the line. Starting the weekend of September 20, the TTC planned to begin a 30-day revenue demonstration test without passengers. Up to 15 trains would operate every five minutes during peak hours, and every seven to ten minutes during off-peak hours. In late October, Metrolinx announced that the 30-day test had been successfully completed and that the line would be turned over to the TTC no later than November 3. On November 24, 2025, the TTC officially announced that the line would open on December 7, 2025. The TTC planned a "soft opening" for the line. Until the second quarter of 2026, the line would end daily service at 10pm to give Mosaic Transit Group extra time for maintenance and to monitor for operating issues. This would avoid the severe startup problems that occurred on the
O-Train Confederation Line in Ottawa. The TTC would run 15 LRVs during peak periods providing a frequency of 6 minutes and 30 seconds. The off-peak frequency would be every 10 to 12 minutes. Bus substitution would be used between 10pm and 1am the following calendar day. As part of the soft opening, trains would operate at less than the originally promised speeds and frequency. The city and Metrolinx had agreed to a speed limit of for trains going through intersections and approaching stops. During planning for the line, Metrolinx had promised a 33-minute run time. At its opening, the line was using "conditional" transit signal priority that activates only if the train is behind schedule. Trains were being trapped by red lights because they could not extend green lights at an intersection, and trains were not allowed through intersections before other traffic, having to defer to left-turning vehicles. It was also observed that trains would dwell for 45 to 90 seconds at on-street stop after the doors had closed for departure. After opening, the round-trip target time became 98 minutes but actual round-trip times could be as much as 120 minutes. Following a motion by Mayor
Olivia Chow on December 16, city council instructed the city manager to work with the TTC and Metrolinx to implement "more aggressive" transit signal priority along Line 6. On December 10, the TTC board had adopted a similar motion. The TTC was also looking at dwell times at stops. For the 29 days of service following its opening, Line 6 had service interruptions on 14 of those days for various reasons, such as intruders, debris on the tracks, and mechanical problems. On January 12, 2026, a switch heater blew a fuse after an electrical power surge, resulting in a three-hour suspension of service. As a result of a major snowstorm on January 15, 2026, the line was closed for a day and a half. Track switches on Line 6 have frequently malfunctioned during winter weather conditions such as icy rain and snow storms because of their electric heaters. The O-Train Confederation Line initially used such heaters, which also resulted in severe problems, but had them replaced with gas-powered heaters. Metrolinx claimed that gas- or hot-air powered heaters could not be used because, unlike the O-Train line, Line 6 is at street level and is crossed by pedestrians and road traffic. By mid-March 2026, the city had made changes to traffic light signals along Finch Avenue to give Line 6 trains priority over left-turning road traffic. Effective March 15, trains would also operate between 10pm and 1am, eliminating the temporary late evening bus substitution. ==Route==