Rainhill is a suburb of St Helens, Merseyside,England.

It was formerly a separate village, then part of Prescot parish and borough.

It was the site of the famous 1829 Rainhill Trials where a number of railway locomotives were entered in a competition to decide a suitable design for use on the new Liverpool and Manchester Railway. The winner was The Rocket, designed by George Stephenson.

The railway still runs through Rainhill. There is a station with frequent services to Liverpool, Manchester and Warrington.