Maria Yegorovna Gaidar (Russian: Мари́я Его́ровна Гайда́р; 1990–2004 Smirnova (Russian: Смирно́ва); born 21 October 1982, Moscow) is a Russian political activist and since July 2015 a vice-governor of Odessa Oblast in Ukraine. From 2009 till 2011 Gaidar was a deputy governor in Kirov Oblast in Russia. She is also the founder of the Youth movement "DA!" ("Yes!").