Nonsuch Mansion is a house located within Nonsuch Park in north Surrey, England. It is on the boundaries of the borough of Epsom and Ewell and the London Borough of Sutton. It is Grade II listed.
In medieval times it was part of the three thousand acre manor of Cuddington. The mansion was built in between 1731 and 1743 by Joseph Thompson and later bought by Samuel Farmer in 1799. He employed Jeffry Wyattville to rebuild it in a Tudor Gothic style in 1802 to 1806. Farmer was succeeded by his grandson in 1838 under whom the gardens became famous. Nonsuch Mansion bears a resemblance in its design to the original design of Nonsuch Palace, whose construction was begun by King Henry VIII in the 16th Century. Built within the north porch of the mansion is a block from the original Nonsuch Palace that bears an inscription which means "1543 Henry VIII in the 35th year of His reign." In 1937 the Farmer family sold the mansion to a group of local authorities.