William Rathbone V (17 June 1787 – 1 February 1868) was an English merchant and politician, serving as Lord Mayor of Liverpool.

[3] The notability and prosperity of the Rathbone family of Liverpool was tied to the growth of that city as a major Atlantic trading port.

William Rathbone was elected a Reformer (Liberal) councillor for the Pitt Street ward in Liverpool in the first ever Council election in 1835,[4] subsequently re-elected in 1837,[5] for the Vauxhall ward in 1845,[6] Lord Mayor of Liverpool in 1837, and fought for social reforms.

He supported Kitty Wilkinson in establishing wash-houses and public baths following the 1832 cholera epidemic, was an active supporter of the Municipal Reform Act 1835, was responsible for the distribution of New England Relief funds during the Irish famine of 1846–1847 (see British Relief Association).

Rathbone married Elizabeth (1790–1882), daughter of Samuel Greg of Quarry Bank Mill, Cheshire and Hannah (née Lightbody) in 1812.