The title Duke of Gloucester (pronounced gloss-tor) is a British royal title (after Gloucester), often conferred on one of the sons of the reigning monarch. The first four creations were in the Peerage of England, the next in the Peerage of Great Britain, and the last in the Peerage of the United Kingdom.

The title was first conferred on Thomas of Woodstock, the thirteenth child of King Edward III. The title became extinct at his death, as it did upon the death of the Duke of the second creation, Humphrey of Lancaster, fifth son of King Henry IV.

The title was next conferred on Richard Plantagenet, brother to King Edward IV. When Richard himself became King, the dukedom merged into the crown. Next to receive the dukedom was the son of King Charles I, Henry Stuart, upon whose death the title became extinct.

William, son of Queen Anne, was styled "Duke of Gloucester" for his whole life (1689-1700), but never created as such.

The next actual creation was for the brother of George III, Prince William Henry, the full title being "Duke of Gloucester and Edinburgh".

The fifth and final creation was for Prince Henry, son of King George V. Upon Prince Henry's death, the dukedom was inherited by his son Prince Richard, who still holds the title. The heir to the title is presently Alexander Windsor, styled Earl of Ulster.

There is a preserved steam locomotive called Duke of Gloucester.

Dukes of Gloucester, first Creation (1385)

• Thomas of Woodstock, Duke of Gloucester (1355-1397)

Dukes of Gloucester, second Creation (1414)

• Humphrey, Duke of Gloucester (1390-1447)

Dukes of Gloucester, third Creation (1461)

• Richard Plantagenet, Duke of Gloucester (1452-1485) (became King in 1483)

Dukes of Gloucester, fourth Creation (1659)

• Henry Stuart, Duke of Gloucester (1640-1660)

Dukes of Gloucester and Edinburgh (1764)

• HRH Prince William Henry, Duke of Gloucester and Edinburgh (1743-1805)
• HRH Prince William Frederick, Duke of Gloucester and Edinburgh (1776-1834)

Dukes of Gloucester, fifth Creation (1928)

• HRH The Prince Henry, Duke of Gloucester (1900-1974)
• HRH Prince Richard, Duke of Gloucester (b. 1944)

Heir Apparent: Alexander Patrick Gregers Richard Windsor, Earl of Ulster (born 24 October 1974)

See also Earl of Gloucester.