Maria Catherina Swanenburg (9 September 1839 – 11 April 1915) was a Dutch serial killer. Maria was the daughter of Clemens Swanenburg and Johanna Dingjan. After her first two daughters died at a young age, she married Johannes van der Linden on 13 May 1868. The result of this marriage was five sons and two daughters. The marriage lasted until 29 January 1886. Her nickname was Goeie Mie (which translates as Good Mee) which she got for taking care of children and ill people in the poor neighbourhood of Leiden in which she lived. She poisoned up to one-hundred people with arsenic of which twenty-seven died between 1880 and 1883, but failed in her attempt to kill at least another fifty using the same method — the investigation included about ninety deaths. Forty-five of the survivors sustained chronic health problems after ingesting the poison. Maria’s motive was the money she would receive either through the victims’ insurance or their inheritance. She secured most of the insurance policies herself.
Her first victim was her own mother in 1880; shortly after this, she killed her father. She was caught when trying to poison the Frankhuizen family in December 1883. Her trial began on April 23, 1885. Maria was found guilty and sentenced to live in a correctional facility for the rest of her life. She died there in 1915.