Thomas Seymour, 1st Baron Seymour of Sudeley, English general and politician, Lord Warden of the Cinque Ports (born 1508)

Thomas Seymour, 1st Baron Seymour of Sudeley, KG, PC was a brother of Jane Seymour, the third wife of King Henry VIII. With his brother, Edward Seymour, 1st Duke of Somerset and Lord Protector of England, he vied for control of their nephew, the young King Edward VI. In 1547, Seymour married Catherine Parr, the widow of Henry VIII. During his marriage to Catherine, Seymour involved the future Queen Elizabeth I, who resided in his household, in flirtatious and possibly sexual behaviour.

Lord Warden of the Cinque Ports is the name of a ceremonial post in the United Kingdom. The post dates from at least the 12th century, when the title was Keeper of the Coast, but it may be older. The Lord Warden was originally in charge of the Cinque Ports, a group of five port towns on the southeast coast of England formed to collectively supply ships for The Crown in the absence of a formal navy at that time. Today, the post is a sinecure and an honorary title, and 14 towns belong to the Cinque Ports confederation. The title is one of the higher honours bestowed by the Sovereign; it has often been held by members of the Royal Family or by prime ministers, especially those who were influential in defending Britain in times of war.