Sir Thomas Mildmay was an English courtier and politician.

He was born the eldest son of Thomas Mildmay (bef.1515–1566), educated at Christ's College, Cambridge and entered Lincoln's Inn in 1559.

He was elected Member of Parliament

Member of Parliament

A Member of Parliament is a representative of the voters to a :parliament. In many countries with bicameral parliaments, the term applies specifically to members of the lower house, as upper houses often have a different title, such as senate, and thus also have different titles for its members,...

 for Lostwithiel

Lostwithiel (UK Parliament constituency)

Lostwithiel was a rotten borough in Cornwall which returned two Members of Parliament to the House of Commons in the English and later British Parliament from 1304 to 1832, when it was abolished by the Great Reform Act.-History:...

 in the Parliament of 1563-1567 and knighted on 23 June 1567. He was then knight of the shire (MP) for Essex

Essex (UK Parliament constituency)

Essex was a constituency represented in the House of Commons of the Parliament of the United Kingdom from 1290 until 1832. It elected two MPs, traditionally referred to as Knights of the Shire, to the House of Commons...

 in 1571. He was Sheriff of Essex

High Sheriff of Essex

The High Sheriff of Essex was an ancient High Sheriff title originating in the time of the Angles, not long after the invasion of the Kingdom of England, which was in existence for around a thousand years...

 for 1572 and the Custos Rotulorum of Essex

Custos Rotulorum of Essex

This is a list of people who have served as custos rotulorum of Essex.* Sir William Petre bef. 1544–1572* Sir Anthony Cooke c. 1573–1576* Sir Thomas Mildmay c. 1577–1608* Thomas Howard, 1st Earl of Suffolk bef...

from 1576 to 1608.

He married firstly Frances, daughter of Henry Radcliffe, 2nd Earl of Sussex, with whom he had three sons and a daughter and, secondly, Margaret Whettle (or Whitwell).