Gertruid (Truuj) Bolwater (died 1511) was a legendary Dutch heroine, known as the defender of Venlo during its siege by Emperor Maximilian I when she climbed up the defence wall of the city and took over the defence wall from a fallen ensign.

You can help expand this article with text translated from the corresponding article in Dutch. (May 2011) Click [show] for important translation instructions. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Dutch Wikipedia article at [[:nl:Gertruid Bolwater]]; see its history for attribution. You should also add the template {{Translated|nl|Gertruid Bolwater}} to the talk page. For more guidance, see Wikipedia:Translation.

She was an important symbol for local patriotism during the 19th century, and has been the subject of publications since the 17th century. Nowadays, however, historians have decided that she was a symbol and not a real person.^{[citation needed]}

During the southern Dutch carnival, on the Thursday before the main event, in the city of Venlo is an all women festivity called Truujendaag in local dialect. It is said to be referring to the heroine. During this day, women dress in medieval clothes and roam the city. No men are allowed to show themselves. If they do, their tie is cut in half.

In recognition of her (alleged) heroic act, a street in the city center was named after her. She also is getting a much criticized clay statue.^{[citation needed]}

• Jac Geurts, en, in: Digitaal Vrouwenlexicon van Nederland.