Marieta de Veintimilla Marconi (1855-1907) was an Ecuadorian writer, feminist and politician.

As first lady, she introduced many changes in dress and social attitude in gender roles: she made the upper class women of Ecuador cast off the black costumes they dressed in at the time and adopt European fashion in bright colors, and she also liberated women's space of movement by making it acceptable for women to walk in the streets without a male guardian as company, after setting an example by doing so herself in her position as first lady, walking about in the streets in public alone or in the company of a female friend.

In 1882, her uncle was absent from the capital of Quito in another part of the country.

When civil war broke out during his absence, she took control of the capital, the government and its military forces in the name of her uncle's office and commanded the defense of Quite when it was attacked by the rebels in 1883.

After her return to Ecuador in 1898, she became a leading figure in the newly founded women's movement in Ecuador as a writer and by making speeches in feminist issues.