Ontario Southland Railway

The Ontario Southland Railway, Inc. is an independently held short line operator. The company was founded in 1992 to purchase 27 km of track between Tillsonburg and Ingersoll, Ontario from the Canadian Pacific Railway (CPR). In 2009, a second line was added, as 51 km of CPR track from Woodstock to St. Thomas, Ontario were integrated into the system. In 2015, Ontario Southland began leasing the ex-Canadian National Cayuga Subdivision between St. Thomas and Delhi, Ontario, which had been abandoned by its former shortline operator the St. Thomas and Eastern Railway in 2013.

OSR also operated the Guelph Junction Railway until 28 August 2020 when operations were transferred to the Goderich–Exeter Railway.

Tillsonburg Operations
OSR's Tillsonburg Division operates on the remaining 28.3 km of the ex-CPR Port Burwell Subdivision between Ingersoll and Tillsonburg, Ontario. Customers served include Future Transfer, Cedar Crest Wood Products, Kissner Group, Johnson Controls, International Beams, and Wellmaster. Traffic destined for Growmark, Inc. in Delhi, Ontario, as well as Cargill and Norfolk Co-Op in Courtland, Ontario is also handled.

St. Thomas Operations
On 14 December 2009, the OSR began leasing the St. Thomas Subdivision from CPR consisting of 54.1 km of track from Woodstock to St. Thomas, Ontario. Customers served include Ontario Refrigerated Services, Auto Warehousing Company, Agrium, Belmont Farm Supply, Sylvite, Messenger Freight Services, and Factor Gas Liquids. Interchange with CN at St. Thomas and with CP at Woodstock.

CAMI Automotive Operations
OSR performs switching at the CAMI Automotive plant in Ingersoll, Ontario. The facility experiences an approximate daily influx and outflow of 100 multis.

Cayuga Subdivision
In November 2015, OSR and Canadian National (CN) Railways made a joint announcement regarding the transfer of operations on CN's disused Cayuga subdivision. The responsibility of managing the St. Thomas–Tillsonburg segment (and extending to Delhi, Ontario) was handed over to OSR. However, this transition would commence after essential track maintenance was carried out, aiming to facilitate the transportation needs of a newly established windmill turbine factory situated east of Tillsonburg. Other customers served include two grain elevators in Courtland, Ontario, an ethanol plant in Aylmer, Ontario and a fertilizer plant in Delhi.