GO Transit, the sole inter-regional public transit system in Southern Ontario, Canada operates numerous bus routes. These buses serve the Greater Toronto and Hamilton Area (GTHA), and the Greater Golden Horseshoe. The GO Transit bus fleet consists of single-level coach buses and double-decker buses. All of the buses are equipped with bike racks.
Each train route has a corresponding GO Bus service for the times (and directions) when (and where) the trains are not operating. These accept the same tickets as the trains and in many cases serve the same stations. For example, buses operate from Toronto to Milton, and from Aldershot station in West Burlington to Hamilton, at all times except the weekday evening peak when trains are available. Some train routes are similarly extended by buses at all times, as noted in the list of routes, with through buses when the trains do not run. For example buses to Guelph operate from Mount Pleasant during peak times, and from Toronto at off-peak times. Buses serving downtown Toronto operate to a terminal adjacent to Union Station.
Other GO Buses are independent of rail services. Some parts of the route network use expressways (such as the frequent Toronto–Hamilton express bus via the Queen Elizabeth Way) while others are more local in character. Toronto Pearson International Airport is served by two routes: one to Yorkdale and Finch subway stations, and one from Hamilton GO Centre to Richmond Hill Centre Terminal.
GO bus fares depend on the origin and destination of the trip. Some local municipal bus services offer fare integration, which offers a lower fare in conjunction with a trip on a GO bus. GO buses also offer the use of the Presto card.