William Austin (1587–1634) was a 17th-century English lawyer, writer, and poet whose sacred verse and nativity carols represent a notable early Stuart contribution to English devotional literature. Born in 1587, he pursued a career in law as a barrister of Lincoln's Inn during the reign of King Charles I. Alongside his legal practice, Austin was deeply devoted to religious study and sacred poetry, circulating his meditative writings and verse privately among contemporary literary circles.

Following his death, his widow, Ann Austin, collected and published his major written legacy in 1635 under the title Devotionis Augustinianae Flamma (The Flame of Augustinian Devotion). This landmark volume contained a series of prose meditations alongside devotional poems and carols for the Christian liturgical calendar, including three carols for Christmas Day, three poems for Good Friday, one for the Feast of the Annunciation, and a solemn meditation written in anticipation of his own death. His work was rediscovered in the 19th century, with several pieces reprinted in collections such as Mozley's Days & Seasons (1857) and Edward Farr's Select Poetry of James I.

Austin is best remembered in hymnology for his early 17th-century Christmas carols, which blend vivid Jacobean imagery with joyful theological reflection. In modern hymnals and carol collections—most notably Bramley and Stainer's Christmas Carols, New and Old—his verse appears in adaptations such as:

• "All this night bright Angels sing" — A joyous nativity carol celebrating the angelic choir over Bethlehem.

• "All this night shrill Chanticleer" — Austin's original opening carol for Christmas Day, featuring the traditional imagery of the dawn rooster proclaiming the birth of Christ.

• "What a gracious God have we" — A hymn of divine providence preserved in the Harleian manuscripts (A Handful of Celestial Flowers).

William Austin died on January 16, 1634, at the age of forty-seven. He was buried in the north transept of St. Saviour's Church (now Southwark Cathedral) in London, where a monument depicts Austin, his wife, and their children.