Kitchener (formerly Georgetown) is one of the seven train lines of the GO Transit system in the Greater Toronto Area, Ontario, Canada. It extends from Union Station in Toronto to Kitchener. GO Bus service to Guelph to and from Georgetown (during rush hours) and Bramalea (during midday) is provided Monday to Friday with evening and weekend service directly to Union Station via Brampton.
The Georgetown line was, after the then-combined Lakeshore West line and Lakeshore East line, the second line established by GO Transit, opened on April 29, 1974 with service from Brampton and Union Station. From October 29, 1990 to July 2, 1993, train service on the line extended beyond Georgetown to Guelph. On December 19, 2011, the Georgetown Line was renamed the Kitchener Line with the opening of an extension to Kitchener, including a restoration of Guelph service.
West Toronto Diamond construction
Under the GO Transit Rail Improvement Program, construction is underway to grade separate the West Toronto Diamond on the Georgetown line. Although planned, approved and funded separately from the Georgetown South Expansion (see below), it falls within the same corridor and was seen as a necessary precursor project. Owing to recent construction delays, construction at West Toronto Diamond and the broader Georgetown South Expansion will now dovetail into one another.
Georgetown South expansion
Following proposals for service expansions along the Georgetown line since at least 1990, a project to provide both Georgetown South Service Expansion and a rail link to Pearson Airport entered a streamlined environmental impact assessment process in early 2009 with Metrolinx now as its proponent. The environmental assessment was completed in July 2009 and final approval was given in October 2009.
The plan would result in an increased frequency of trains on the route, from approximately 50 per day to at least 300. It drew criticism from Weston community groups, which opposed the increased use of diesel locomotives emitting pollutants in their area, preferring instead that the corridor be electrified. The group has also requested more stations to provide service for more neighbourhoods along the route.
GO Transit is also planning to expand its service for the Kitchener line to all-day, two-way operations. It purchased the 25 km Weston Subdivision segment of rail from Canadian National Railway, from downtown Toronto to Bramalea Road, so that it may control train dispatching along that segment. CNR will continue to operate three daily local freight trains along that corridor, and Via Rail will now lease line operations from GO Transit for routes along that corridor, though GO Transit trains will receive signalling priority.
A new station is also proposed where the line crosses Eglinton Avenue in the Mount Dennis neighbourhood; it would interface with the western end of the Eglinton Crosstown LRT line, at Mount Dennis LRT station, and open when that line opens in about 2022. 
In September 2008, GO Transit unveiled a proposal to extend the line past Georgetown to Acton, Guelph, and Kitchener. In the final Environmental Study Report released in July 2009, the extension was identified as both viable and preferable to bus service. The report selected the following sites for four new stations:
- Georgetown - current GO Station to be retained and expanded in its current location
- Acton - to be located at the former GO Station site at Hide House
- Guelph - to be located at the existing Via station and former GO Station in that city's downtown
- Breslau - to be located on the eastern side of the village at the end of an extended Greenhouse Road. Would serve as the primary park and ride facility for entire Waterloo Region.
- Kitchener - to be located in that city's downtown at the existing Via station on an interim basis, and then ultimately relocated three blocks west to a new multimodal station on King Street with connectivity to the proposed LRT line.
A layover yard, potentially expandable to a full refueling and servicing facility, would be constructed on the western side of Baden. The report suggests passenger service could be added to this facility (akin to Lincolnville GO Station) at a later date, as well as identifying Rockwood as a potential location for an infill station as demand warrants.
In November 2010, a limited rollout of the above plan was announced to be in place by late 2011. Two trains daily were planned to serve Acton, Guelph and Kitchener (the latter two at their existing Via locations); layover for those trains would be at a small facility in Kitchener. $18 million would be spent to get this first stage operational, with further upgrades to come. Service to Guelph and Kitchener began December 19; the line was renamed the 'Kitchener GO Train line' on the same date. The Acton station's opening was delayed until January 7, 2013.
The Kitchener line makes connections with:
- Ion (transit system) (Future)
- Brampton Transit
- Grand River Transit
- Guelph Transit
- Toronto Transit Commission
- Cameron, Roger (1 April 2009). "Reduces Corporate Taxes, Sales Tax Harmonization". Railway Association of Canada. Retrieved 22 April 2009.
- http://www.metrolinx.com/gsse/archive/ Metrolinx Georgetown South Service Expansion - Archived Reports & Publications
- http://www.metrolinx.com/Docs/News/Project_START_News_Release_Final_Dec_15.pdf News Release - Metrolinx is new proponent of Georgetown Line
- http://www.newswire.ca/en/releases/archive/January2009/21/c9235.html January 21 Metrolinx announcement
- Kalinowski, Tess (22 April 2009). "GO plans anger residents". Toronto Star. Retrieved 22 April 2009.
- Kalinowski, Tess (9 April 2009). "Train service to improve to Georgetown, Brampton". Toronto Star. Retrieved 22 April 2009.
- "GO Transit acquires important CN rail line for expanded commuter rail service in the Greater Toronto Area". PR Newswire Association LLC. Canadian National Railway. 8 April 2009. Retrieved 22 April 2009.
- James Bow (2013-09-04). "Future Mount Dennis Station (Kitchener Line/Eglinton LRT)". Transit Toronto. Retrieved 2013-09-08. "The connection was given new life with the launch of Eglinton LRT, operating from Jane Street east to Kennedy. A stop near Black Creek Drive would include a connection with the GO Kitchener line and a new stop on the Union Pearson Express."
- R. J. Burnside and Associates, Ltd. (2009-07-13). "Georgetown to Kitchener Environmental Study Report". Retrieved 2010-11-21.
- Outhit, Jeff (14 November 2010). "GO trains to run from Kitchener to Toronto in 2011". Waterloo Region Record. Retrieved 14 November 2010.
- Outhit, Jeff (25 November 2011). "GO Train coming Dec. 19". Waterloo Region Record. Retrieved 25 November 2011.
- "GO station to be built in Acton". Guelph Mercury. 27 July 2012. Retrieved 27 July 2012.
- GO Transit: Kitchener GO Train & Bus Service Schedule (PDF)
- GO Transit's Kitchener Line on Transit Toronto