There have been two Baronetcies created for the Onslow family, one in the Baronetage of England and one in the Baronetage of Great Britain. Both titles are still extant.

The Onslow Baronetcy, of West Clandon in the County of Surrey, was created in the Baronetage of England on 8 May 1674 for Arthur Onslow

Sir Arthur Onslow, 1st Baronet

Sir Arthur Onslow, 1st Baronet was an English politicianThe eldest son of Sir Richard Onslow, an important Parliamentarian from Surrey, Arthur also took an active role in political affairs during the English Civil War. He represented Bramber in the Long Parliament, and Surrey in the First, Second,...

, with the precedence of 1660. The second Baronet was created Baron Onslow in 1716 and the fourth Baron was created Earl of Onslow

Earl of Onslow

Earl of Onslow, of Onslow in the County of Shropshire, is a title in the Peerage of the United Kingdom. It was created in 1801 for George Onslow, 4th Baron Onslow. The Onslow family descends from Arthur Onslow, who represented Bramber, Sussex and Guildford in the House of Commons...

 in 1801. Form more information on this creation, see the latter title.

The Onslow Baronetcy, of Althain in the County of Lancaster, was created in the Baronetage of Great Britain on 30 October 1797 for the naval commander Admiral Sir Richard Onslow

Sir Richard Onslow, 1st Baronet

Sir Richard Onslow, 1st Baronet GCB was an English naval officer who played a distinguished role at the Battle of Camperdown.-Naval career:...

. The title was awarded in recognition of his services at the Battle of Camperdown

Battle of Camperdown

The Battle of Camperdown was a major naval action fought on 11 October 1797 between a Royal Navy fleet under Admiral Adam Duncan and a Dutch Navy fleet under Vice-Admiral Jan de Winter...

 where he was second in command. Onslow was the second son of Lieutenant-General Richard Onslow

Richard Onslow (British Army officer)

Lieutenant-General Richard Onslow was a British army officer and politician.He was the second son of Foot Onslow and the younger brother of Arthur Onslow, Speaker of the House of Commons. On 9 December 1726, he married his brother's sister-in-law, Rose Bridges, daughter of John Bridges of Thames...

, nephew of the first Baron Onslow and uncle of the first Earl of Onslow. The present holder of the baronetcy is also in remainder to the Onslow Baronetcy of West Clandon and in special remainder to the barony of Onslow.

Onslow Baronets, of Althain (1797)

• Sir Richard Onslow, 1st Baronet
  Sir Richard Onslow, 1st Baronet
  Sir Richard Onslow, 1st Baronet GCB was an English naval officer who played a distinguished role at the Battle of Camperdown.-Naval career:...
  
  (1741–1817)
• Sir Henry Onslow, 2nd Baronet (1784–1853)
• Sir Henry Onslow, 3rd Baronet (1809–1870)
• Sir Matthew Richard Onslow, 4th Baronet (1810–1876)
• Sir William Wallace Rhoderic Onslow, 5th Baronet (1845–1916)
• Sir Roger Warin Beaconsfield Onslow, 6th Baronet (1880–1931)
• Sir Richard Wilmot Onslow, 7th Baronet (1906–1963)
• Sir John Roger Wilmot Onslow, 8th Baronet (1932–2009)
• Sir Richard Paul Atherton Onslow, 9th Baronet (b. 1958)