Pieter Feddes Hiemstra (4 August 1878 – 9 January 1953) was a Dutch trade union leader and politician.
[1][2] Hiemstra also joined the Social Democratic Workers' Party (SDAP), and later became the chair of its Leeuwarden executive.
[1] Under Hiemstra's leadership, the union grew, and in 1920, it organised a conference which led to the formation of the International Landworkers' Federation (ILF).
Hiemstra became its first general secretary, although in 1924 its headquarters were moved to Germany to save on translation costs, and he switched to become vice president.
The same year, he was elected to the House of Representatives, where he argued for shorter working hours and better benefits for agricultural workers.