Events from the year 1650 in England, second year of the Third English Civil War.

• 1 May – claimant King Charles II of England signs the Treaty of Breda with the Scottish Covenanters.
• 10 May – Commonwealth (Adultery) Act (1650) imposes the death penalty for incest, and for adultery, that is defined as sexual intercourse between a married woman and a man other than her husband. Both partners would be liable for death sentence in such a case, although the courts are reluctant to impose the ultimate penalty.^[1] If a man (married or unmarried) has sex with an unmarried woman (including a widow), that would be fornication, punishable only by three months for first offenders, applicable to both partners.^[1][2] In the history of adultery in English law, this represents the only time since the twelfth century when adultery has been outlawed in secular statute law.^[3]
• 17 May – a quarter of the New Model Army at the Siege of Clonmel in Ireland is trapped and killed.
• 26 May – Oliver Cromwell leaves Ireland (following the Siege of Clonmel), occasioning Andrew Marvell's An Horatian Ode upon Cromwell's Return from Ireland.
• 23 June – Charles arrives in Scotland (at Garmouth) where he signs the Covenant.^[4]
• 13 August – Colonel George Monck forms Monck's Regiment of Foot, forerunner of the Coldstream Guards.
• 3 September – Oliver Cromwell is victorious over the Scottish Covenanters at the Battle of Dunbar, opening the Anglo-Scottish war (1650–1652).^[4]
• 19 September – With the Treaty of Hartford, the Dutch and English establish the frontiers between their colonies in North America.^[5]
• 29 September – Henry Robinson opens his Office of Addresses and Encounters, a form of employment exchange, in Threadneedle Street, London.
• 30 October – the Religious Society of Friends acquires the nickname "Quakers" when the judge at George Fox's blasphemy trial says that they "tremble at the word of the Lord".^[6]
• 14 December – Anne Greene is hanged at Oxford Castle for infanticide, having concealed an illegitimate stillbirth. The following day she revives in the dissection room and, being pardoned, lives until 1665.^[7][8]

• 2 February (?) – Nell Gwyn, actress and royal mistress (died 1687)
• 24 March – Sir Jonathan Trelawny, 3rd Baronet, bishop (died 1721)
• 18 April – Sir Edward Dering, 3rd Baronet, Member of Parliament (died 1689)
• 20 April – William Bedloe, informer (died 1680)
• 1 May (bapt.) – John Radcliffe, physician (died 1714)
• 26 May – John Churchill, 1st Duke of Marlborough, general (died 1722)
• 14 September – Theophilus Oglethorpe, soldier and Member of Parliament (died 1702)
• 23 September – Jeremy Collier, theatre critic, non-juror bishop and theologian (died 1726)
• 20 October – Robert Shirley, 1st Earl Ferrers, courtier (died 1717)
• 7 November – John Robinson, diplomat (died 1723)
• November – Cloudesley Shovell, admiral (died 1707)
• 14 November – King William III of England, Scotland, and Ireland (died 1702)
• 1 December (bapt.) – William Talman, architect (died 1719)
• Undated
  • George Rooke, admiral (died 1709)
  • Richard Lumley, 1st Earl of Scarbrough, statesman (died 1721)
• Approximate date
  • Solomon de Medina, French-born army contractor (died 1720)
  • Charlotte Paston, Countess of Yarmouth, née FitzRoy, noblewoman, illegitimate daughter of Charles II (died 1684)

• February – Sir Thomas Bowyer, 1st Baronet, politician (born 1586)
• 9 March – Elizabeth Savage, Countess Rivers, courtier (born 1581)
• 18 April – Simonds d'Ewes, antiquarian and politician (born 1602)
• 9 July (burial) – Alice Barnham, wife of Francis Bacon (born 1592)
• 25 August – Richard Crashaw, poet (born c. 1613)
• 8 September – Princess Elizabeth of England, daughter of Charles I (born 1635)
• 13 November – Thomas May, poet and historian (born 1595)
• 13 December – Phineas Fletcher, poet (born 1582)
• 25 December – Thomas Cooper, former Usher of Gresham's School and Royalist, hanged
• Probable date – Isaac Ewer, soldier and regicide (year of birth unknown)