Klaas de Jonge (29 June 1887 – 19 April 1958) was a Dutch trade union leader.
In 1913, he was the first social democrat to win election to the local council, and in 1914, he became district secretary of the SDAP.
That year, he began working full-time for the NVvFA, while in 1915, he won election to the council in Winschoten.
[1][2] During World War II, de Jonge was arrested twice, being imprisoned on the first occasion, and sent to a concentration camp in Germany on the second.
He was liberated at the end of the war, but spent several months recuperating in hospital before he was able to return to Amsterdam.