John Ruskin (8 February 1819 – 20 January 1900) is the leading English art critic of the Victorian era, also an art patron, draftsman, watercolorist, a prominent social thinker and philanthropist.

He writes on subjects ranging from geology to architecture, myth to ornithology, literature to education, and botany to political economy.

His writing styles and literary forms are equally varied.

Ruskin pens essays and treatises, poetry and lectures, travel guides and manuals, letters and even a fairy tale.

The elaborate style that characterizes his earliest writing on art is later superseded by a preference for plainer language designed to communicate his ideas more effectively.

In all of his writing, he emphasizes the connections between nature, art and society.

He also makes detailed sketches and paintings of rocks, plants, birds, landscapes, and architectural structures and ornamentation.

He is hugely influential in the latter half of the 19th century up to the First World War.

After a period of relative decline, his reputation has steadily improved since the 1960s with the publication of numerous academic studies of his work.

Today, his ideas and concerns are widely recognized as having anticipated interest in environmentalism, sustainability and craft.

Ruskin first comes to widespread attention with the first volume of Modern Painters (1843), an extended essay in defense of the work of J. M. W. Turner in which he argues that the principal role of the artist is "truth to nature".

From the 1850s, he champions the Pre-Raphaelites who are influenced by his ideas.

His work increasingly focuses on social and political issues.

Unto This Last (1860, 1862) marks the shift in emphasis.

In 1869, Ruskin becomes the first Slade Professor of Fine Art at the University of Oxford, where he establishes the Ruskin School of Drawing.

In 1871, he begins his monthly "letters to the workmen and labourers of Great Britain", published under the title Fors Clavigera (1871–1884).

In the course of this complex and deeply personal work, he develops the principles underlying his ideal society.

As a result, he founds the Guild of St. George, an organization that endures today.