Mainline Freight was a trainload rail freight operator based in Islington, London, England with operations extending to Yorkshire in the north and Somerset in the west.

Mainline Freight, Loadhaul and Transrail were purchased by a consortium led by Wisconsin Central in 1996 and amalgamated into a new company, English Welsh & Scottish.

Mainline Freight was created in 1994 along with Transrail and Loadhaul as part of the broadly regional split of British Rail's Trainload Freight operations – Mainline Freight's centre of operations were South East England, and East Anglia, and the East Midlands.

[1] It was initially and briefly named "Trainload Freight South East Limited" before being re-branded in September 1994.

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