Duncan Dunbar (1803–1862) was a Scottish businessman and London-based shipowner who established what was described as the largest shipping line in Great Britain.

[2] Duncan was born on 8 September 1803 at 7 Fore Street, Limehouse, London, Middlesex.

His father Duncan Dunbar Sr. had moved to London in the 1790s and founded a successful business as a brewer and wine merchant.

[1] He settled in Limehouse in the 1790s, establishing his alcohol business at Dunbar Wharf.

[1] A noted protectionist,[3] Duncan Jr. possessed the largest sailing fleet in the world in the mid-19th century.