Sir Joshua Walmsley (1794–1871) was an English businessman and Liberal Party politician.
The son of John Walmsley, an architect, builder and marble mason, he was born in Liverpool on 29 September 1794, and educated at Knowsley, Lancashire, and Eden Hall, Westmorland. On the death of his father in 1807, Walmsley became a teacher in Eden Hall school, and after returning to Liverpool in 1811, he took a teaching position in Mr. Knowles's school. He entered the service of a corn merchant in 1814, and at the end of this engagement went into the same business himself.
He was an early advocate of the repeal of the duty on corn, and was afterwards an active worker with Richard Cobden, John Bright, and others in the Anti-Cornlaw League. In 1826 he took the presidency of the Liverpool Mechanics' Institution. At about the same time Walmsley got to know George Stephenson, in whose railway schemes he was interested, and with whom he joined in purchasing the Snibstone estate, near Ashby-de-la-Zouch, where rich seams of coal were found. He was elected a member of the Liverpool town council in 1835, and worked to improve the police, sanitation and education of the city. He was appointed Mayor in November 1838, and knighted on the occasion of Queen Victoria's marriage.
With Lord Palmerston, Walmsley unsuccessfully contested Liverpool in the Liberal interest in June 1841. He retired to Ranton Abbey, Staffordshire, in 1843, and at the general election of 1847 was elected M.P. for Leicester, but was unseated on petition. He started the National Reform Association about this time, and was its president and chief organiser for many years. In 1849 he was returned as M.P. for Bolton in Lancashire, but in 1852 exchanged that seat for Leicester, where his efforts on behalf of the framework knitters had made him popular. He lost his seat in 1857, and he practically retired from public life, although he retained the presidency of the National Sunday League from 1856 to 1869.