Robert Smythson (1535–1614) i an English architect.
Smythson designs a number of notable houses during the Elizabethan era.
Little is known about his birth and upbringing—his first mention in historical records comes in 1556, when he is stonemason for the house at Longleat, built by Sir John Thynne (c. 1512-1580).
He later designs Hardwick Hall, Wollaton Hall, Burghley House, Burton Agnes Hall, and other significant projects.
Historically, a number of other Elizabethan houses, such as Gawthorpe Hall, have been attributed to him on stylistic grounds.