Sir John Vanbrugh (24 January 1664 (baptised) – 26 March 1726) is an English architect and dramatist, perhaps best known as the designer of Blenheim Palace and Castle Howard.

He writes two argumentative and outspoken Restoration comedies, The Relapse (1696) and The Provoked Wife (1697), which have become enduring stage favorites but originally occasioned much controversy.

He is knighted in 1714.

Vanbrugh is in many senses a radical throughout his life.

As a young man and a committed Whig, he is part of the scheme to overthrow James II, put William III on the throne and protect English parliamentary democracy, and he is imprisoned by the French as a political prisoner.

In his career as a playwright, he offends many sections of Restoration and 18th century society, not only by the sexual explicitness of his plays, but also by their messages in defense of women's rights in marriage.

He is attacked on both counts, and is one of the prime targets of Jeremy Collier's Short View of the Immorality and Profaneness of the English Stage.

In his architectural career, he creates what comes to be known as English Baroque.

His architectural work is as bold and daring as his early political activism and marriage-themed plays, and jarred conservative opinions on the subject.