Maarja Kivi (born January 18, 1986 in Tallinn, Estonia) is an Estonian singer and former member of the girl group Vanilla Ninja. Born to Riina and Madis Kivi. She has a brother, Vahur and two sisters, Helen and Kristi.

She started her career in the spotlight by competing in the 2002 Eurolaul, the Estonian competition to find an entry for the Eurovision Song Contest. Later that year she became one of the original four members of Vanilla Ninja, taking on the lead vocals and role of bassist in most tracks on their first two albums, Vanilla Ninja and Traces Of Sadness. Kivi left the group in mid-2004 due to make real rock and metal music not pop-rock, and was replaced by Triinu Kivilaan.