Kaczynski or Kaczyński (feminine: Kaczyńska, plural: Kaczyńscy) is a Polish language surname. Notable people with the name include:
Andrew Kaczynski, American journalist and political reporter for BuzzFeed
Bogusław Kaczyński (born 1942), Polish classical music journalist
David Kaczynski (born 1949), American activist, Theodore Kaczynski's brother
Jarosław Kaczyński (born 1949), Polish politician, former prime minister of Poland
Lech Kaczyński (1949–2010), Polish politician, former president of Poland, Jarosław Kaczyński's twin brother
Maria Kaczyńska (1942–2010), Polish economist, Lech Kaczyński's wife
Richard Kaczynski, American writer
Ryszard Kaczyński (born 1954), Polish politician
Theodore Kaczynski (born 1942), American mathematician, social critic, and serial bomber, known as the Unabomber
