Herman or Hermanus VI van Woerden (ca. 1240 – after 1303) was a lord of Woerden.
He was the son of Herman V van Woerden and Badeloch Clemeta van Amstel, daughter of Gijsbrecht III van Amstel. It is assumed he became ruler of Woerden after 1252, the last year that his father was mentioned. He pledged his loyalty to the bishop of Utrecht as his father had done before him, but he nonetheless desired to expand his territory. In the 1280s the lands between the County of Holland and the Bishopric of Utrecht were sold to Floris V, Count of Holland. These lands included Woerden, which made Herman a vassal of the count of Holland. Herman was not happy with this, and several conflicts followed. in 1288 the count of Holland and Herman van Woerden reconciled.
Herman took part in the conspiracy to kidnap Floris V, Count of Holland. Together with Gerard van Velsen and Gijsbrecht IV of Amstel he imprisoned the count in the Muiderslot after capturing him by setting up a fake Falconry hunt. After the local population got wind of their count's imprisonment, they rebelled. When Floris attempted to escape, Gerard van Velsen killed him with a dagger. Herman fled and just like Gijsbrecht managed to reach Amstel, from where he went into Exile. Subsequently he lost all his titles and lands.
Herman VI married in 1265 with Elizabeth van Brederode, a daughter of William II, Count of Brederode and Hildegonda van Voorne. From this marriage he had a daughter named Clementa van Woerden(1265–1316). Herman supposedly married for a second time in 1287 with Elisabeth van Amstel.
He may have died in Flanders between 1303 and 1304.