It is an optional station stop on the Via Rail Toronto-Ottawa-Montreal Corridor line for two trains a day in each direction.

Both westbound trains arrive from Montreal and continue towards Ottawa, Kingston, and Toronto.

The first eastbound train arrives from Toronto, Kingston, and Ottawa and continues towards Montreal, while the second eastbound train arrives from Ottawa only and continues to Montreal.

As of September 2020, Casselman station is served by 1 domestic route (with connections) provided by Via Rail, the primary passenger rail operator in Canada.

Departures have been reduced to 4 trains per day due to the coronavirus pandemic (effective September 1, 2020).