James Muspratt (12 August 1793 – 4 May 1886) was a British chemical manufacturer who was the first to make alkali by the Leblanc process on a large scale in the United Kingdom.

He followed the British army on foot into the interior, was laid up with fever at Madrid, and, narrowly escaping capture by the French, succeeded in making his way to Lisbon where he joined the navy.

Here he began to manufacture chemical products such as hydrochloric and acetic acids and turpentine, adding prussiate of potash a few years later.

Muspratt was attracted towards manufacturing it, but could not raise the capital for the relatively expensive Leblanc plant and also considered that Dublin was not a suitable location for this.

[4] In 1828 he built works at St Helens, (then in Lancashire), in partnership with Josias Gamble, another Irish-born chemist.

[7] In 1838 after a trial lasting three days, with 40 witnesses for the prosecution and 46 for the defence, a jury found Muspratt guilty of "creating and maintaining a nuisance".

[8] In 1851 Muspratt largely withdrew from the business although he supported his sons, Richard and Frederic in starting new alkali works at Wood End, Widnes and Flint.