He was educated at
Norwich School and
Trinity College, Cambridge, becoming a fellow of his college in 1585 and public orator of the university in 1594.
Robert Devereux, 2nd Earl of Essex, commissioned him to spend some time abroad, sending information about European affairs. On his return, Naunton was elected
Member of Parliament for
Helston at a by-election in 1606. Naunton visited the court in London in October 1605. He thought that
Anne of Denmark's
farthingale might conceal a pregnancy, writing, "The Queen is generally held to be pregnant, but no appearance eminent by reason of the short vardugals in use". On 7 September 1615, Naunton was knighted. In 1616, he became
Master of Requests and later surveyor of the court of wards. In December 1617 his friend
George Villiers, 1st Duke of Buckingham procured for him the position of
Secretary of State on the condition of his making
Christopher Villiers, Buckingham's brother, his heir, and during his lifetime Villiers gained from Naunton estates worth £500 a year. In 1621 Naunton was elected MP for
Cambridge University. His strong
Protestant opinions led him to favour more active intervention by England in the interests of
Frederick V, Elector Palatine, and more vigorous application of the laws against Roman Catholics. Naunton was censured after the
Spanish ambassador,
Gondomar, complained to
King James I. Consequently, in January 1623, Naunton resigned as Secretary of State and was made master of the
Court of Wards and Liveries. Sir Robert was re-elected MP for Cambridge University in 1624 and 1625. He was elected MP for
Suffolk in 1626. Naunton died at
Letheringham,
Suffolk at the age of 71. ==Marriages and issue==