Lewis Henry Steiner (May 4, 1827 – February 18, 1892) was an American medical doctor and librarian.

[1] Soon after he began to practise his attention was especially directed to chemistry and the allied sciences, and during his residence in Baltimore his time was largely occupied in teaching.

[2] In 1871 he was elected by the Republicans to the Maryland Senate, representing Frederick County for four years.

[5] In 1884 he was appointed librarian of the Enoch Pratt Free Library, remaining there until his death.

They had six children, of which one, his son Bernard Christian Steiner, succeeded his father as librarian.