Mont-Saint-Hilaire (also designated line 13) is a commuter rail service in Greater Montreal, Quebec.

CN rolling stock in the late 1960s and early 1970s, operated once daily each direction, was a hodgepodge of ca 1930 coaches and an equally eclectic mix of yard switchers, freight and passenger diesel electric engines.

The Mont-Saint-Hilaire line was re-opened in 2000 (between Montreal Central Station and McMasterville) by the AMT as a measure to mitigate traffic congestion caused by roadwork.

[4] In 2019, civic organization Trajectoire Québec proposed several improvements to the Mont-Saint-Hilaire line, which has seen little service changes since the early-2000s.

Among such proposals are increasing the frequency of trains to accommodate passengers transferring from South Shore bus services that would no longer directly run to Downtown Montreal following the opening of the Réseau express métropolitain, relocating the Saint-Bruno station closer to residential neighbourhoods and potentially extending passenger service to Saint-Hyacinthe.