|Covid-19|Monarch – Gustav III
7 January – Johan Henrik Hästesko is arrested for involvement in the Anjala conspiracy.
January – King Gustav III summon the Riksdag of the Estates to Stockholm.
21 February – King Gustav III has three of four estates pass to the Union and Security Act against the will of the nobility.
April - The Riksdag of the Estates is dissolved.
A group supported by Princess Charlotte, Princess Sophia Albertina, Prince Frederick Adolf of Sweden and Gustaf Adolf Reuterholm attempts to use the discontent among to nobility toward the war and the Union and Security Act to depose the King in favor of his brother Duke Charles, but fail.
May - The Supreme Court of Sweden is founded.
12 May - Stjärnorp Castle burns down.
13 June - Battle of Porrassalmi
28 June - Battle of Uttismalm
21 July - Battle of Parkumäki
26 July - Battle of Öland (1789)
24 August - First Battle of Svensksund
- A large group of female members of the court and aristocracy, led by the examples of Princess Charlotte, Princess Sophia Albertina and Jeanna von Lantingshausen, unleash a social boycott of the monarch in protest of the Union and Security Act.
- The Swedish National Debt Office is founded.
- The privileges of the nobility from 1723 is abolished.
- The peasantry of the state are allowed to hunt freely.
För tapperhet i fält
3 January - Martina von Schwerin, Lady of letters, salonist and culture personality (died 1)
- Elisabeth Charlotta Karsten, painter (died 1856)
- Johanna Hård, pirate (died 1851)
9 May – Anders Johan von Höpken, politician (born 1712)
25 May – Anders Dahl, botanist (born 1751)
- Françoise Marguerite Janiçon, writer (born 1711)
- Hedvig Löfwenskiöld, poet (born 1736)
1789 in Sweden Wikipedia
Events from the year 1789 in Sweden