There have been three Baronetcies created for members of the Sedley ( otherwise Sidley) family of Kent, all in the Baronetage of England. All three creations are extinct.

All the Baronets descend from the 15th century family of Aylesford

Aylesford

Aylesford is a village and civil parish on the River Medway in Kent, 4 miles NW of Maidstone in England.Originally a small riverside settlement, the old village comprises around 60 houses, many of which were formerly shops. One pub, a Post Office and four small independent shops remain...

 and Scadbury, Southfleet

Southfleet

Southfleet is a small compact village five miles SW of Gravesend in Kent; it is a civil parish within the borough of Dartford, and includes within its boundaries the hamlet of Betsham, and the even smaller settlement of Northfleet Green. The main village is grouped around a crossroads and many of...

 and from William Sedley of Southfleet who was High Sheriff of Kent

High Sheriff of Kent

The High Sheriff is the oldest secular office under the Crown. Formerly the High Sheriff was the principal law enforcement officer in the county but over the centuries most of the responsibilities associated with the post have been transferred elsewhere or are now defunct, so that its functions...

 in 1546.

The Baronetcy of Sedley of Aylesford in the County of Kent, was created in the Baronetage of England on 29 June 1611 for William Sedley of The Friars, Aylesford. He was High Sheriff

High Sheriff

A high sheriff is, or was, a law enforcement officer in the United Kingdom, Canada and the United States.In England and Wales, the office is unpaid and partly ceremonial, appointed by the Crown through a warrant from the Privy Council. In Cornwall, the High Sheriff is appointed by the Duke of...

 of the county in 1589. His son, the second Baronet, was High Sheriff in 1621. He was succeeded in turn by his three sons, the third of whom, the fifth Baronet, was a politician, wit and dramatist. His only legitimate child was Catherine Sedley, Countess of Dorchester, mistress of James II

James II of England

James II & VII was King of England and King of Ireland as James II and King of Scotland as James VII, from 6 February 1685. He was the last Catholic monarch to reign over the Kingdoms of England, Scotland, and Ireland...

. The title became extinct on his death in 1701.

The Baronetcy Sedley of Great Chart in the County of Kent, was created in the Baronetage of England on 24 September 1621 for Isaack Sedley, a grandson of the 1st Baronet of Aylesford by his third son Nicholas. He was High Sheriff of Kent in 1626. The title became extinct on the death of the eighth Baronet in circa 1770.

The Baronetcy Sedley of Southfleet in the County of Kent, was created in the Baronetage of England on 10 July 1702 for Charles Sedley, the grandson of the fifth Baronet of Aylesford by an illegitimate son Charles. The second Baronet sat as 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 Nottingham

Nottingham (UK Parliament constituency)

Nottingham was a parliamentary borough in Nottinghamshire, which elected two Members of Parliament to the House of Commons from 1295. In 1885 the constituency was abolished and the city of Nottingham divided into three single-member constituencies....

. The title became extinct on his death in 1778.

Sedley Baronets, of Ailesford (1611)

• Sir William Sedley, 1st Baronet (c. 1558-1618)
• Sir John Sedley, 2nd Baronet (c. 1597-1638)
• Sir Henry Sedley, 3rd Baronet (c. 1623-1641)
• Sir William Sedley, 4th Baronet (d. 1656)
• Sir Charles Sedley, 5th Baronet (1639-1701)

Sedley Baronets, of Great Chart (1621)

• Sir Isaack Sedley, 1st Baronet (d. 1627)
• Sir John Sedley, 2nd Baronet (c. 1600-1673)
• Sir Isaac Sedley, 3rd Baronet (d. by 1695)
• Sir Charles Sedley, 4th Baronet (d. 1702)
• Sir John Sedley, 5th Baronet (c. 1710)
• Sir George Sedley, 6th Baronet (d. by 1722)
• Sir George Sedley, 7th Baronet (d. 1737)
• Sir Charles Sedley, 8th Baronet (d. c. 1770)

Sedley Baronets, of Southfleet (1702)

• Sir Charles Sedley, 1st Baronet (c. 1695-1730)
• Sir Charles Sedley, 2nd Baronet
  Sir Charles Sedley, 2nd Baronet
  Sir Charles Sedley, 2nd Baronet , was a British politician.Sedley was the son of Sir Charles Sedley, 1st Baronet, son of Sir Charles Sedley, illegitimate son of Sir Charles Sedley, 5th Baronet. He sat as Member of Parliament for Nottingham from 1747 to 1754 and 1774 to 1778.Sedley died in August...
  
  (c. 1721-1778)