|Covid-19|February 28 – The Scottish National Covenant is signed in Edinburgh, Scotland.
March 3 – A mercenary army under Bernard of Saxe-Weimar fighting for France defeats imperial forces at the Battle of Rheinfelden.
March 5 – Thirty Years' War – The Treaty of Hamburg is signed by France and Sweden.
March 29 – Settlers from Sweden arrive on the ships Kalmar Nyckel and Fogel Grip to establish the settlement of New Sweden in Delaware, beginning the Swedish colonization of the Americas.
March – Anne Hutchinson is banished from the Massachusetts Bay Colony for heresy and goes to Rhode Island.
April 3 – John Wheelwright is banished from Boston and founds Exeter, New Hampshire.
April 15 – Shogunate forces defeat the last remnants of the Shimabara Rebellion in the fortress of Hara.
May 13 – Construction begins on the Red Fort in Delhi (India) for Mughal Emperor Shah Jahan who is transferring his capital there from Agra.
May 23 – Signing of the Kandyan Treaty between the Singhala King Rajasimha II and the Dutch to rid Ceylon of the Portuguese.
June 20 – Spanish troops under Ferdinand of Austria defeat a much larger Dutch force near Antwerp at the Battle of Kallo during the Eighty Years' War.
June 27 – Patriarch Cyril of Constantinople is deposed for high treason and strangled and thrown into the sea by Janissaries on Ottoman Sultan Murad IV's command.
September 21 – The Treaty of Hartford is signed, ending the Pequot War between British American colonists and the Pequot.
September – John Spofford arrives in Boston Harbor on the ship John of London and is one of the first people to establish Rowely, Essex County, Massachusetts.
October 21 – The Great Thunderstorm breaks out in Widecombe-in-the-Moor, England.
November – The General Assembly of the Church of Scotland is summoned to Glasgow by King Charles I of England.
December 18 – Mazarin becomes first adviser to French potentate Richelieu on the death of Leclerc du Tremblay.
December 21 – The full moon is in total eclipse from 1:12 to 2:47 UT and the solstice occurs later in the day at 16:05 UT.
Scottish Covenanters meet at Muchalls Castle to compose responses to the Bishops of Aberdeen.
Pedro Teixeira makes the first ascent of the Amazon River, from its mouth to Quito, Ecuador. The same trip had been made in the opposite direction in 1541.
Dutch merchant Willem Kieft is appointed Director of New Amsterdam by the Dutch West India Company.
The Netherlands colonizes Mauritius.
The Dutch settle in Ceylon.
The Finnish postal service, Suomen Posti, is founded.
New Haven, the first planned city in America, is founded.
Sultan Murad IV captures Baghdad.
Mughal Emperor Shah Jahan and his sons capture the city of Kandahar from the Safavids.
Shipwrecked English buccaneer Peter Wallace called "Ballis" by the Spanish, settles near and perhaps gives his name to the Belize River, the first known European settlement in Belize.
The Beijing Gazette makes an official switch in its production process of newspapers, from woodblock printing to movable type printing; private newspapers in Ming dynasty China were first mentioned in 1582.
Antoinette du Ligier de la Garde Deshoulières, French writer (d. 1694)
Emperor Go-Sai, of Japan (d. 1685)
Nicolas Steno, Danish pioneer in anatomy and geology, bishop (d. 1686)
Filippo Bonanni, Italian Jesuit scholar (d. 1723)
Marie Elisabeth of Brunswick-Wolfenbüttel, German noblewoman (d. 1687)
January 8 – Elisabetta Sirani, Italian painter (d. 1665)
January 12 – Ernst Rüdiger von Starhemberg, Austrian field marshal (d. 1701)
January 20 – Sir William Glynne, 1st Baronet, English politician (d. 1690)
David Elias Heidenreich, German poet, dramatist, librettist and translator (d. 1688)
Beata Rosenhane, Swedish writer (d. 1674)
January 24 – Charles Sackville, 6th Earl of Dorset, English poet and courtier (d. 1706)
February 12 – Frederick, Duke of Mecklenburg-Grabow, German nobleman, titular Duke of Mecklenburg (d. 1688)
February 18 – Ikeda Tsunamasa, Japanese daimyo, ruler of the Okayama Domain (d. 1714)
February 25 – Jørgen Iversen Dyppel, Governor of the Danish West Indies (d. 1683)
February 28 – John Carmichael, 1st Earl of Hyndford, Scottish nobleman (d. 1710)
Henry Capell, 1st Baron Capell of Tewkesbury, First Lord of the British Admiralty (d. 1696)
Statz Friedrich von Fullen, nobleman and a Geheimrat of war (d. 1703)
March 10 – John Vesey, Irish archbishop (d. 1716)
March 14 – Johann Georg Gichtel, German mystic and religious leader who was a critic of Lutheranism (d. 1710)
March 15 – Shunzhi Emperor (d. 1661)
March 16 – François Crépieul, Jesuit missionary in Canada (d. 1702)
March 28 – Frederik Ruysch, Dutch physician and anatomist (d. 1731)
Sir Henry Beaumont, 2nd Baronet, English politician (d. 1689)
John Covel, clergyman and scientist, Master of Christ's College (d. 1722)
May 9 – Gregorio Vasquez de Arce y Ceballos, Colombian painter (d. 1711)
May 11 – Guy-Crescent Fagon, French physician and botanist (d. 1718)
May 12 – Pedro Atanasio Bocanegra, Spanish artist (d. 1688)
May 13 – Richard Simon, French Biblical critic (d. 1712)
May 29 – John Manners, 1st Duke of Rutland, English nobleman and politician (d. 1711)
June 2 – Henry Hyde, 2nd Earl of Clarendon, English nobleman (d. 1709)
June 3 – Thomas Smith, English scholar (d. 1710)
June 8 – Pierre Magnol, French botanist (d. 1715)
June 21 – Sir William Roberts, 1st Baronet, English politician (d. 1688)
June 23 – Princess Christine Elisabeth of Schleswig-Holstein-Sonderburg, German noblewoman (d. 1679)
June 27 – Samuel Frisching, Bernese soldier and politician (d. 1721)
June 28 – Louise Marie de La Grange d'Arquien, French noblewoman (d. 1728)
June 29 – Heinrich Meibom, German physicist and scholar (d. 1700)
July 10 – David Teniers III, Flemish painter (d. 1685)
July 11 – Olympia Mancini, French courtier (d. 1708)
July 15 – Giovanni Buonaventura Viviani, Italian composer (d. 1693)
July 20 – Ulrik Frederik Gyldenløve, leading general in Norway during the Scanian War (d. 1704)
July 25 – Cristobal of Saint Catherine (d. 1690)
August 3 – William Louis, Prince of Anhalt-Köthen (1650–1665) (d. 1665)
August 6 – Nicolas Malebranche, French philosopher (d. 1715)
August 7 – John Tufton, 4th Earl of Thanet, English politician (d. 1680)
August 13 – Durgadas Rathore, Indian ruler (d. 1718)
August 15 – Pieter de Graeff, Dutch politician and noble (d. 1707)
August 22 – Georg Christoph Eimmart, German engraver (d. 1705)
September 5 – King Louis XIV of France, King of France from 1643 until his death (d. 1715)
September 10 – Maria Theresa of Spain, wife of Louis XIV of France (d. 1683)
September 19 – Isaac Milles, English minister (d. 1720)
September 20 – Antonio Gherardi, Italian painter (d. 1702)
September 21 – Philippe de Courcillon, French officer and author (d. 1720)
September 30 – Maximilian Philipp Hieronymus, Duke of Bavaria-Leuchtenberg, German nobleman (d. 1705)
October 7 – Miguel Jerónimo de Molina, Spanish prelate, Bishop of Malta, then of Lleida in Catalonia (d. 1698)
October 14 – Bernhard II, Duke of Saxe-Jena, German noble (d. 1678)
October 17 – John Charles, Count Palatine of Gelnhausen (1654–1704) (d. 1704)
October 21 – Lucia Wijbrants, Dutch artist (d. 1719)
October 31 – Meindert Hobbema, Dutch painter (d. 1709)
November 4 – Nuno Álvares Pereira de Melo, 1st Duke of Cadaval, Portuguese nobleman and statesman (d. 1725)
November 8 – Anton van Dale, Dutch minister (d. 1708)
November 22 – Christoph Cellarius, German classical scholar (d. 1707)
November 25 – Catherine of Braganza, wife of Charles II of England (d. 1705)
November 30 – Joachim Feller, German professor at the University of Leipzig (d. 1691)
December 17 – Anna Sophia II, Abbess of Quedlinburg, Abbesses of Quedlinburg (d. 1683)
December 24 – Tomás de la Cerda, 3rd Marquis of la Laguna, Spanish nobleman (d. 1692)
December 25 – Michel Bégon, French ancien regime official (d. 1710)
January 21 – Ignazio Donati, Italian composer (b. c. 1570)
January 27 – Gonzalo de Céspedes y Meneses, Spanish novelist (b. c. 1585)
February 26 – Claude Gaspard Bachet de Méziriac, French mathematician (b. 1581)
April 7 – Shimazu Tadatsune, Japanese ruler of Satsuma (b. 1576)
April 13 – Henri, Duke of Rohan, French Huguenot leader (b. 1579)
May 6 – Cornelius Jansen, French bishop and religious reformer (b. 1585)
May 27 – Pietro Paolo Floriani, architect (b. 1585)
June 25 – Juan Pérez de Montalbán, Spanish writer (b. 1602)
September - Christoph Besold, German jurist (b. 1577)
September 14 – John Harvard, American clergyman (b. 1607)
November 9 – Johann Heinrich Alsted, German theologian (b. 1588)
November 11 – Cornelis Corneliszoon van Haarlem, Dutch painter (b. 1562)
December 8 – Ivan Gundulić, Croatian poet (b. 1589)
1638 (MDCXXXVIII) was a common year starting on Friday (dominical letter C) of the Gregorian calendar and a common year starting on Monday (dominical letter G) of the Julian calendar, the 1638th year of the Common Era (CE) and Anno Domini (AD) designations, the 638th year of the 2nd millennium, the 38th year of the 17th century, and the 9th year of the 1630s decade. As of the start of 1638, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.