William Henry Monk (16 March 1823 – 1 March 1889) was an English church musician, composer and editor. He is best known for his tune EVENTIDE, which is used as the standard setting for the hymn "Abide with Me".

Born in London, he was educated at King's College London, and subsequently became professor of vocal music there. He was appointed organist and choirmaster at St Matthias' Church, Stoke Newington, in 1847, remaining there until 1849. In 1849 he took a similar post at St Barnabas', Pimlico, where he stayed for ten years. From 1855 he was professor at the School for the Indigent Blind. In 1859 he became musical editor of *Hymns Ancient and Modern*, a hugely influential hymnal, and from 1876 until his death he was organist and choirmaster at All Saints', Margaret Street, London.

Monk's most enduring composition is his hymn tune EVENTIDE, written in 1861. The story often told is that he composed it after witnessing a particularly beautiful sunset. It was first published in 1861 in *Hymns Ancient and Modern*, set to Henry Francis Lyte's hymn "Abide with Me". The combination of words and tune has become one of the most popular hymns in the English language.

Besides his work on *Hymns Ancient and Modern*, Monk edited several other hymnals and collections of church music. He also composed anthems, hymn tunes, and other sacred works. He was a strong advocate for the improvement of church music, and his work had a significant influence on the development of hymnody in the 19th century.

Monk was also active as an organist, giving recitals and teaching. He was a Fellow of the Royal College of Organists. He died in London in 1889.

William Henry Monk is remembered today primarily for EVENTIDE, a tune that continues to resonate deeply with people around the world. His contribution to church music extends beyond this one work, however, and his legacy as an editor, composer, and advocate for musical excellence in worship is significant.