Maria Catherina Swanenburg (Leiden 9 September 1839 - Gorinchem 11 April 1915) was a Dutch serial killer, who murdered at least 27, and was suspected of killing more than 90 people.

Swanenburg 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, also spelt as Goede Mie in modern Dutch (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.

It was established with certainty she poisoned at least 102 people with arsenic of which 27 died between 1880 and 1883. The investigation included more than ninety suspicious deaths. Forty-five of the survivors sustained chronic health problems after ingesting the poison.

Swanenburg's motive was the money she would receive either through the victims' insurance or their inheritance. She had secured most of the insurance policies herself. Her first victim was her own mother in 1880; shortly after this, she killed her father too.

She was caught when trying to poison the Frankhuizen family in December 1883. Her trial began on April 23, 1885. Maria Swanenburg was found guilty of murder of her last three victims and sentenced to live in a correctional facility for the rest of her life. She died there in 1915.

Maria Swanenburg