Fontanka (in Russian, Фонтанка) is the left branch of the river Neva, which flows through the whole of St. Petersburg. Russia. Its embankment is lined with private residences of the Russian nobility.

Fontanka is one of 93 rivers and channels in St. Petersburg. This river was once named Anonymous Creek (in Russian, Bezymyannyi Yerik, Безымянный ерик). In Russian language, yerik is a secondary or intermittent river channel (creek or brook).

The river received such its new name because water from it was taken for fountains of the Summer Garden.