Maria Kuliabicheva, known professionally as River Decleyre, is a filmmaker based in Sintra, Portugal. She was born in Tatarstan, Russia, in 1986.

In 2014, Decleyre moved to Berlin, Germany, to work as a personal assistant to director Aleksander Bach on the 20th Century Fox motion picture, Hitman: Agent 47.

In 2018, she moved to Portugal where she began her writing career. In 2022, she directed her first short film, A Night in Lisbon.

The main themes of her work include love, loss, Eros, polarity between masculine and feminine, and mental health struggles.