Henry Farrer (March 23, 1844 – February 24, 1903) was an English-born American artist known for his tonalist watercolor landscapes and etchings.

Thomas had studied in Britain under John Ruskin and Dante Gabriel Rossetti, members of the Pre-Raphaelite Brotherhood.

As a newcomer to the American art world, he became a member of the Society for the Advancement of Truth in Art, a short-lived organization co-founded by his brother and centered on the Pre-Raphaelite tradition of truthful and highly realistic artistic depictions.

In his first years as a professional artist in the 1860s, Farrer painted Pre-Raphaelite still lives, some landscapes and marine works, and also began his first efforts at etching.

He co-founded the American Watercolor Society and, unlike most artists of the time, painted in water colours almost exclusively.