30850) is a preserved British steam locomotive of the Lord Nelson class.

It forms part of the United Kingdom's National Railway Collection.

850 was built at Eastleigh Works in 1926 to a design by R E L Maunsell, as the prototype for the sixteen-strong Lord Nelson class, and named after Horatio Nelson.

It was preserved as part of the National Railway Collection, and is the sole survivor of the class.

It has run in preservation, including on the main line, where its TOPS number is 98750.