Duchess Marie Louise of Mecklenburg-Schwerin (German: Herzogin Marie Luise Friederike Alexandrine Elisabeth Charlotte Catherine Mecklenburg-Schwerin; 31 March 1803 – 26 October 1862) was the Duchess of Saxe-Altenburg.

Frederick Louis was the son of Frederick Francis I, Grand Duke of Mecklenburg-Schwerin, and Princess Louise of Saxe-Gotha-Altenburg, while Elena Pavlovna was the daughter of Paul I of Russia and Duchess Sophie Dorothea of Württemberg.

On 7 October 1825 in Ludwigslust, at the age of 22, Marie Louise married 29-year-old Georg, Duke of Saxe-Altenburg.

Georg was the son of Frederick, Duke of Saxe-Altenburg, and Duchess Charlotte Georgine of Mecklenburg-Strelitz.

The local superintendent Klötzner said: "[...] in his love for his wife and sons, he was the model of a real family man.