The train, expected to arrive at Toronto’s Union Station around 12:50 p.m. this afternoon, was travelling through Barrhaven, outside Ottawa, when it hit the double-decker OC Transpo bus.
Via Rail says no major injuries were reported on the train.
The train was numbered 51 from Montreal, and it just left the Ottawa station and was pulling into Fallowfield station for an 8:52 departure.
Via Rail suspended train service between Ottawa and Brockville, replacing the trains with buses, in light of the accident.
The 103 passengers on the train will be bused to Toronto. A line up of Ottawa-bound travellers waiting for buses could be seen at Union Station this morning.
Toronto-bound Via passenger David Hugill told CBC News: "It's horrible. What can I say? It was really undramatic on the train. It certainly didn't feel like it was an incident of that magnitude from where we were sitting.
"It's a brutal, brutal thing."
Hugill, a PhD candidate at York University, later tweeted:
The last time Toronto saw a train-bus collision of this magnitude was on Friday, December 12, 1975, when a full bus stalled on train tracks in Scarborough and was struck by a Go Train, killing eight people and injuring 21.